Hi
Inorder to use functions of a dll you must know the parameters, if you do not have the function proto in some header file then you should find out the parameters by debugging and/or disassembling the dll, reading the code will help to find the number of parameters and what they should be while passing to the function. a useful hint is to look at the return point of the function, there should be some ADD esp,n where n maybe the number of bytes pushed into stack before calling the function, and n is a multiple of 4.

Thanks
--Ali