>Nadya,
>If you have the Visual Studio Tools installed, take a look at Depends.Exe. It will not only tell you what files you need to run a DLL/EXE/OCX, it will also display the functions available in the specified file. It does not give you the parameters for a given function but this is one step closer.

If it's a COM DLL, use the OLE/COM Viewer. Use the View Typelib option from the File menu. The typelib can be kind of tricky to read, but it not only gives you the function names, it gives you the parameters and datatypes as well.

You could also use the Typelib Information DLL, but it's a bit more work. Randy Brown's MSMQ article has an example of how to use this (http://msdn.microsoft.com/library/default.asp?URL=/library/techart/msmqwvfp6.htm). You have to do some coding, but once you're done, you'll have a handy utility you can use again.