Hi, RobiNew! Sometimes my lack of good knowledge helps me to find simple solutions. Here you are:
Code:
Sub LastNameRN()
'Select the range from the 1st para's start until the para's 1st comma.
Set oRng = ActiveDocument.Paragraphs(1).range
If InStr(1, oRng, ",") > 0 Then
oRng.Collapse
oRng.MoveEndUntil Cset:=","
oRng.Select
End If
End Sub