SaveAs new filename not SaveAs copy

I was wondering how to make a macro call SaveAs and not save it as a new copy.  I am trying to just rename a file in my code and not make a copy.  What I have so far is a code that saves the file as one of the custom properties but it ends up saving a new copy.  Here is my macro.

Set swApp = Application.SldWorks

Set swModel = swApp.ActiveDoc

Set swModelDocExt = swModel.Extension

Set swCustProp = swModelDocExt.CustomPropertyManager("")

swCustProp.Get2 "Part Number", val, valout

PathName = swModel.GetPathName

Filepath = Left(PathName, InStrRev(PathName, "\"))

If (swModel.GetType = swDocASSEMBLY) Then

    swModel.SaveAs (Filepath & valout & ".sldasm")

    'swModel.SaveAs (Filepath + strPaste + ".sldasm")

ElseIf (swModel.GetType = swDocPART) Then

     swModel.SaveAs (Filepath & valout & ".sldprt")

SolidworksApi macros