Just some questions at first glance
 Code:
;Select data range (cell at bottom right of data range)
$RC = $objExcel.Range("A1:P1285")
Is your excel sheet always 1285 rows deep?

 Code:
    ;Save the workbook with as name the manager
    $RC = $objExcel.ActiveWorkbook.SaveAs@SCRIPTDIR+"\"+$Manager+".xls",,,,,False)
I think you missed a "(" here:
$RC = $objExcel.ActiveWorkbook.SaveAs(@SCRIPTDIR+"\"+$Manager+".xls",,,,,False)

Have you tested your code while editing your script? As far as I can see and as far as I could test your script, you did not select anything so there wasn't anything to copy to the clipboard.

Maybe KiXtarter can help you to run your script from time to time while you are writing it.