com dll

hi all
i have downloaded a mfc com dll in vc++ from net. but i m not able to use it in my vb interface as i never made a com dll and never used that before i compiled the source code and made the dll using cdecl calling convention and registered that but i m not able to view the global functions and variable or classes in the vb project after adding the refrence to the llibrary.
plz help
its very urgent i hav spent my 3 daz on it but no result
Regards,
Rishabh

Whats the dll?

this is implementation of smpp protocol and its in vc++ 6. with several classes and member functions and interface methods