Do you mean does the string always start with Alpha characters? If so, yes however there maybe alpha characters at the end of the string also. Example: "ARM7196C"
Const MYSTRING = "ARM1234C"
Dim intIndex As Integer
Dim strNew As String
For intIndex = 1 To Len(MYSTRING)
If IsNumeric(Mid$(MYSTRING, intIndex, 1)) Then
strNew = strNew & Mid$(MYSTRING, intIndex, 1)
End If
Next
MsgBox strNew