Insert Commas Into a String

[Simonc64]

Hi All

I found this VBA code on the forum which is really helpful, but not really understanding how it works I cant answer my subsidiary question.

The code is

Function InsertCommas(S As String) As String
InsertCommas = Application.Substitute(Replace(StrConv(S, vbUnicode), Chr(0), ","), ",", "", Len(S))
End Function

What Id like to do now is restrict this to only placing commas either immediately before a numeric value or immediately after a text value.

Can this be done?

Thanks

simon