Run bat when SO Invoice posts

I thought this would be easy but could use some insight to get this working. I have *.bat file that launches an external process related to AR Invoice History data. I'd like for the bat file to launch when SO Invoices post. I found some previous comments and thought the following would work for me. 

retval = oScript.Execute("CALL ""[wdx]SYZDLL;SHELL_AND_WAIT""," _
& """""""\\ClientName\Sage\Test Process\Invoice Test.bat"""" ")

Appreciate any help!

~Chris