[PM]

What do you need this for and what is the exact use case? Do you know the number of arguments 'p3' should contain and their types at compile time?

If not, you'll probably have to push the arguments on the stack according to the calling convention ( __cdecl or some varaint ) yourself using inline assembly. That would not be very easy to do (because "basic" types, floating point types, bigger types (structs, classes) can be each passed in a different way + you should respect copy constructors etc. for structs and classes)