Checking the association for chm on my system reveals it is opened with hh.exe, which does accept params but at a glance it does not look like any of them are going to help you much.
The API Htmlhelp function may be worth a look, though I am not sure that would do what you want either besides which it is in hhctrl.ocx and I am not at all sure about trying to call functions in ocx files, could be they are just like regular DLLs though.
The API Htmlhelp function may be worth a look, though I am not sure that would do what you want either besides which it is in hhctrl.ocx and I am not at all sure about trying to call functions in ocx files, could be they are just like regular DLLs though.