Welcome to KORG!

ERROR 2 is "file not found", so likely Kix isn't finding your VBS script.

Also - "start" runs in a separate shell, so the result may not be passed back.

When I write
Shell 'cscript //nologo C:\temp\tst.vbs'
and the tst.vbs contains
result = 47
wscript.quit result
, Kix reports @ERROR of 47, as desired.

Actually I am a Rocket Scientist! \:D