Help, *.CHM, etc

[Tom]

A question for gui application programmers. . . 
I 've got some GUI programs, written in Python/wxPython, and I've got
a help button and a help menu item.  Also, I've got a compiled file
made with the microsoft HTML workshop utility, lets call it
c:\path\help.chm.  My question is how do you launch it from the GUI? 
What logic do I put behind the "help" button, in other words.

I thought it would be

os.spawnv(os.P_DETACH, "c:\\path\\help.chm", [])

but I get an error:

OSError: [Errno 8]  Exec format error

so I guess help.chm isn't executable itself, but is associated with
some unknown executable.  I tried explorer.exe- at the dos cmd line it
basically works to type

explorer.exe c:\path\help.chm

although there is a nag screen that would be nice to do without.

so you'd think 

os.spawnv(os.P_DETACH, 'explorer.exe', ["c:\\path\\help.chm"])

would be equivalent but it fails.  I have to believe someone out there
in python community likes to include help.chm with their applications,
nad there is a right way to do this.

On another note, are there pure python based help viewers that people
use instead?  The reason I ask is that would be more portable then the
*.chm files are.  If there is such a beast I can't find it.