Can anyone explain to me how FOXISAPI finds an object within an EXE?

When I create a VFP application for the web and compile it as a DLL, then register it on my server and call it with FOXISAPI, it seems to work OK.

If, however, I compile it as an EXE I get an error message which says 'class id not found'.

My question: when I pass an EXE name to FOXISAPI like foxisapi.dll/foxis.employee.startup, how does FOXISAPI know which EXE to run?

Should I be using DLL's instead of EXE's?

TIA