VBA File Dialog .FileName removing .1 from end of file name - vba

Question

I am using visual basic to write a Macro for Autodesk Inventor. I created a macro that calls a file dialog, see code below. Everything works fine except when a user puts a file name in with a period and a number greater than zero following it.
For example, if a user puts testfile.test in the box and hits ok. When I ask for what they put in there using .FileName, I get "testfile.test". Just like I should.
However, if the user puts testfile.1 or testfile.10 or testfile.1mdksj or anything as long as a number greater than zero directly follows the period I get back "testfile". For some reason, everything after the period and the period gets removed.
What is the reason for this? Is this a bug in visual basic or am I doing something wrong?
'Set up the file dialog
Dim oFileDlg As FileDialog
' Create a new FileDialog object.
Call ThisApplication.CreateFileDialog(oFileDlg)
'Define the filter to select part and assembly files or any file.
oFileDlg.Filter = "All Files (*.*)|*.*"
'Define the part and assembly files filter to be the default filter.
oFileDlg.FilterIndex = 1
'Set the title for the dialog.
oFileDlg.DialogTitle = "Save File As"
'Tell the dialog box to throw up and error when cancel is hit by user
oFileDlg.CancelError = True
'Show the file dialog
On Error Resume Next
oFileDlg.ShowSave
'save the user specified file
Dim newFileName As String
newFileName = oFileDlg.FileName
UPDATE:
I ended up doing the following "hack" to make things still work while dealing with a period:
oFileDlg.fileName = sFname & "."
oFileDlg.ShowSave
fullName = Left$(oFileDlg.fileName, Len(oFileDlg.fileName) - 1)
That worked fine for quite a while on Windows 7 and then Windows 10. Unfortunately, the Windows 10 Creative update seems to have changed how the file dialog works. With the above code, fullName would come back blank if there were no periods in the name and would truncate everything from the FIRST period from the left if there was a period in the name.
I'm not really sure what changed in Windows 10, but it pretty much destroyed my hack. Windows 7 still works fine and Windows 10 before the creative update works. I ended up doing the following to make everything work again in the version of Windows I mentioned above.
oFileDlg.fileName = sFname & ".00"
oFileDlg.ShowSave
fullName = Left$(oFileDlg.fileName, Len(oFileDlg.fileName) - 3)

Answer 1

This is a VB property, but it may extend to VBA as well. Have you tried setting the save settings to support multidotted extensions? Try something like this:
SupportMultiDottedExtensions = True
This setting is intended permit the use dotted extensions - meaning the use of periods in the file name. See this MSDN reference for documentation and information: http://msdn.microsoft.com/en-us/library/system.windows.forms.filedialog.supportmultidottedextensions.aspx#Y129
This SO article may also shed further light: SaveAs Dialog with a period in the filename does not return extension
EDIT
After checking the autodesk documentation - a difficult and unpleasant task, in my opinion - there does indeed appear to be no support for MultidottedExtensions. I did, however, find a function on VBAExpress that I have very closely adapted. The function can be used to filter strings with contain unacceptable characters. Jimmy Pena's blog has an excellent function for just such a purpose: http://www.jpsoftwaretech.com/excel-vba/validate-filenames/. I have only substantively added a period and a replace to the code:
'A function for filtering strings, with a focus on filenames.
Function FilterFileNameString(stringToScrub As String) As String
'Filters a filename string - or any string for that matter.
Dim FilteredString As String
'A highly nested replace function.
FilteredString = Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(stringToScrub, ".","|", ""), ">", ""), "<", ""), Chr(34), ""), "?", ""), "*", ""), ":", ""), "/", ""), "\", "")
'Returns filtered string.
FilterFileNameString = FilteredString
End Function
Jimmy Pena's blog also contains a recursive version as well, although he does not recommend it.
You can filter any strings to be used as filenames with another character - a space in this case. You could use an underscore, however, or any other character you deemed pleasant.
In general, if you are trying to use periods for versioning or a similar purpose, and inventor will not let you, I would strongly advise going to another character or set of characters that can provide such an indication, such an underscore "_", a numbering system, "001", "002", a lettering system, "AAA", "AAB", or whatever makes sense for your focus.
If you are just making the application user-friendly, I would suggest filtering the strings entered before saving them in the desired filetype, and separate the filtering of the strings from the save dialog if the period filtering gives you grief. It may add an extra step, but it may be the best and easiest way to filter out pesky invalid characters without creating unnecessary extra hassles for your users.
~JOL