Hi!
Under Windows - yes, COM support is right there, although I never tried it. For Linux, I think I saw something to this effect on the Internet but I am afraid COM support would be rudimentary in Linux (and maybe non-existant). If you have a Windows NT and Linux box on the provider, you can communicate with the Windows machine to talk to the ActiveX and get results back. If communication is only one way, you could try other techniques such as passing arguments to a page hosting an ActiveX control on another machine and getting results back.
Best,
Stanislav