hola

aca esta mi funcion
Private Function IsNumeric_TGa(str As String) As Boolean
Dim sAux As String
Dim lPos As Long, lCont As Long, lAsc As Long
lPos = 1
Do While lPos <= Len(str)
IsNumeric_TGa = True
sAux = Mid$(str, lPos, 1)
lAsc = Asc(sAux)
If (lAsc >= 48 And lAsc <= 57) Or (lAsc >= 43 And lAsc <= 46) Then
If lAsc = 44 Then
lCont = lCont + 1
If lCont > 1 Then
IsNumeric_TGa = False
Exit Function
End If
End If
Else
IsNumeric_TGa = False
Exit Function
End If
lPos = lPos + 1
Loop
End Function
Modificado: Espero que ahora funcione