VBA Script to Combine Duplicate Data into One Row - vba

Question

I'm attempting to write a script to, given a list of parts and their used-on numbers, combine the used-on values for all duplicate parts and sort the resulting values. That sounded confusing so here is an image of what I'm shooting for:
Desired Result
It should be able to handle duplicates and blanks.
Through a combination of research and tinkering, I've gotten a sortWithinCell function made, but my headaches are coming from writing the script to iterate down the list of parts, combining used-on values as you go, and then upon reaching a different part number, delete all but the first row that you started from and then continue. Assume that the input parts list is already sorted by part number.
Thanks all!
-Edit 1-
I did manage to find a way to combine the data values:
Function ConcatinateAllCellValuesInRange(sourceRange As Excel.Range) As String
Dim finalValue As String
Dim cell As Excel.Range
For Each cell In sourceRange.Cells
finalValue = finalValue + "," + CStr(cell.Value)
Next cell
ConcatinateAllCellValuesInRange = Right(finalValue, Len(finalValue) - 1)
End Function
However, now the trick is still identifying the input range for this function, i.e. when the part number changes.

Answer 1

A possibile solution would be to create a collection which uses the Part as Key and has the Used-On values as value, so at the first occurence of Part, the KeyValue pair is added, then in an ongoing loop, if the key already exists in the collection, take the value of the key and the one from the collection, merge them together, delete the current KeyValue pair and add a new one (You can't modify a KeyValue pair of a collection, therefore delete the old one and add a new one).
If you are finished looping through your list, you can loop through the elements in the collection and save them somewhere else on the sheet. Or if you want, delete the current range and insert everything where the old values were.
Let me know if you need help with this
EDIT
Here is an example of the method I described, though i used a Dictionary instead of a Collection, because it has more functionality (REQUIRES A REFERENCE TO "Microsoft Scripting Runtime"):
Option Explicit
Sub combineStuff()
'Create Dictionary
Dim tmpDic As New Dictionary
'tempstring to preserve the value of a key
Dim tmpValue As String
Dim i As Integer
'Loop through rows - change this to your needs
For i = 1 To 15 Step 1
'Simple check if "Part" and "Used-On" are both filled
If Cells(i, 1).Value <> "" And Cells(i, 2).Value <> "" Then
'Check if the Key already exists
If tmpDic.Exists(CStr(Cells(i, 1).Value)) Then
'If it does, save it's value
tmpValue = tmpDic.Item(CStr(Cells(i, 1).Value))
'Delete the Key Value pair
tmpDic.Remove CStr(Cells(i, 1).Value)
'Add Key Value pair with updated Value
tmpDic.Add CStr(Cells(i, 1).Value), tmpValue & "," & CStr(Cells(i, 2).Value)
Else
'Key does not exist yet, add it
tmpDic.Add CStr(Cells(i, 1).Value), Cells(i, 2).Value
End If
End If
Next i
Dim tmpKey As Variant
i = 1
'Loop through all items in the Dictionary
For Each tmpKey In tmpDic
'Insert Key
Cells(i, 4).Value = tmpKey
'Insert Value
Cells(i, 5).Value = tmpDic(tmpKey)
i = i + 1
Next tmpKey
End Sub
Note that the Dictionary will not be sorted! The key that was modified last is the last one in the list. If you want the outcome to be sorted, it might be better to use a multidimensional array to store the key and value pairs. Then you can easily sort those.