If you can devise some sort of "rule" regarding which commas to get rid of, then something can probably written to do this. But you have to have some methodology for determining which ones to keep and which ones to get rid of.
I see you got an answer that works, so this is probably a moot point, but since I took the time to write it, I'll post it anyway.
Here is a macro that automatically "fixes" the commas for all the rows in the column the active cell is in:
Application.ScreenUpdating = False
' Get rid of multiple commas
Dim myColumn As Byte
myColumn = ActiveCell.Column
Columns(myColumn).Replace What:=",,", Replacement:=",", LookAt:=xlPart, _
' Get rid if commas at the beginning and end
Dim i As Long
For i = 1 To 65536
If Left(Cells(i, myColumn), 1) = "," Then
Cells(i, myColumn) = Right(Cells(i, myColumn), Len(Cells(i, myColumn)) - 1)
If Right(Cells(i, myColumn), 1) = "," Then
Cells(i, myColumn) = Left(Cells(i, myColumn), Len(Cells(i, myColumn)) - 1)
Application.ScreenUpdating = True
If you run it, it automatically fixes the entries without creating any new columns or formulas.