Maybe you could use a little macro:
Option Explicit
Sub testme()
Selection.Replace What:=",", Replacement:=Chr(9), LookAt:=xlPart, _
SearchOrder:=xlByRows, MatchCase:=False
End Sub
If this is a one time shot, you could just run that one line.
Select your range to convert.
hit alt-f11 (to get to the VBE)
hit ctrl-G
copy these two lines and paste them in that immediate window.
Selection.Replace What:=",", Replacement:=Chr(9), LookAt:=xlPart, _
SearchOrder:=xlByRows, MatchCase:=False
Then hit enter.
Then swap back to excel and see if it worked.