Have you looked at or tested Stephens code?  The third argument of the
ConvertReportToPDF function is for the OutputPDFname.  His documentation
clearly states:
' OutputPDFname is the name you select for the output PDF file

Since you want to use the filename later in your code all you need do is to
specify it when you call the ConvertReportToPDF function.  Presumbly the
ConvertReportToPDF function will save the PDF file where ever you tell it
to.

Perhaps I do not understand what it is that you are trying to do here.