Я полагаю, вам нужно будет заменить замену на находку и заменуЧто-то вроде:
Dim c As Range
Columns("F:M").Select
Set c = Selection.Find(What:=",", LookAt:=xlPart, _
SearchOrder:=xlByRows, MatchCase:=True, SearchFormat:=False)
If Not c Is Nothing Then
Do
c.Replace What:=",", Replacement:="", LookAt:=xlPart, _
SearchOrder:=xlByRows, MatchCase:=True, SearchFormat:=False, _
ReplaceFormat:=False
Cells(c.Row, 1).Value = Date
Set c = Selection.FindNext(c)
Loop While Not c Is Nothing
End If