You can always use the Shell() function to run Excel and open the document.
You can also create an Excel object in VBA code, but for this purpose, Shell
might be easier.
ex.
public sub OpenExcelFile( filename As String )
Shell("excel.exe """ & filename & """")
end sub
And in your macro make the line after your export a RunCode macro, running
the OpenExcelFile subroutine. If there is no need to generate the file name
(it's constant), then you could also do all this without the subroutine by
making the RunCode line in the macro a RunApp macro instead, with the
command line property
excel.exe "<filename with path>"