Query or VBA Function for adding leading zeroes to a field with special conditions - vba

Question

I have a macro I am trying to turn into a VBA Function or Query for adding leading zeros to a field.
For my circumstances, their needs to be 4 numeric digits plus any alphabetic characters that follow so a simple format query doesn't do the trick.
The macro I have uses Evaluate and =Match but I am unsure how this could be achieved in Access.
Sub Change_Number_Format_In_String()
Dim iFirstLetterPosition As Integer
Dim sTemp As String
For Each c In Range("A2:A100")
If Len(c) > 0 Then
iFirstLetterPosition = Evaluate("=MATCH(TRUE,NOT(ISNUMBER(1*MID(" & c.Address & ",ROW($1:$20),1))),0)")
sTemp = Left(c, iFirstLetterPosition - 1) 'get the leading numbers
sTemp = Format(sTemp, "0000") 'format the numbers
sTemp = sTemp & Mid(c, iFirstLetterPosition, Len(c)) 'concatenate the remainder of the string
c.NumberFormat = "#"
c.Value = sTemp
End If
Next
End Sub
In my database the field in need of formatting is called PIDNUMBER
EDIT:
To expand on why FORMAT doesnt work in my situation. Some PIDNUMBERS have an alpha character after the number that should not be counted when determining how many zeroes to add.
In example:
12 should become 0012
12A should become 0012A
When using format, it counts the letters as part of the string, so 12A would become 012A instead of 0012A as intended.

Answer 1

You could try:
Public Function customFormat(ByRef sString As String) As String
customFormat = Right("0000" & sString, 4 + Len(sString) - Len(CStr(Val(sString))))
End Function

Answer 2

Try utilize this function, if you only want this to be available in VBA, put Private in front of the Function:
Function ZeroPadFront(oIn As Variant) As String
Dim zeros As Long, sOut As String
sOut = CStr(oIn)
zeros = 4 - Len(sOut)
If zeros < 0 Then zeros = 0
ZeroPadFront = String(zeros, "0") & sOut
End Function

Answer 3

The Val() function converts a string to a number, and strips off any trailing non-numeric characters. We can use it to figure out how many digits the numeric portion has:
Function PadAlpha$(s$)
Dim NumDigs As Long
NumDigs = Len(CStr(Val(s)))
If NumDigs < 4 Then
PadAlpha = String$(4 - NumDigs, "0") & s
Else
PadAlpha = s
End If
End Function
? padalpha("12")
> 0012
? padalpha("12a")
> 0012a

Answer 4

Bill,
See if this will work. It seems like a function would better suit you.
Function NewPIDNumber(varPIDNumber As Variant) As String
Dim lngLoop As Long
Dim strChar As String
For lngLoop = 1 to Len(varPIDNumber)
strChar = Mid(varPIDNumber, lngLoop, 1)
If IsNumeric(strChar) Then
NewPIDNumber = NewPIDNumber & strChar
Else
Exit For
End If
Next lngLoop
If Len(NewPIDNumber) > 4 Then
MsgBox "Bad Data Maaaaan...." & Chr(13) & Chr(13) & "The record = " & varPIDNumber
Exit Function
End If
Do Until Len(NewPIDNumber) = 4
NewPIDNumber = "0" & NewPIDNumber
Loop
End Function
Data Result
012a 0012
12a 0012
12 0012
85 0085
85adfe 0085
1002a 1002
1002 1002