How can I use callbacks with as many parameters as I want?

I mean something like this for example (pseudocode):

Code:
void c_callback(userdata)
{
  call_python_function(userdata, my);
}

[...]
my.event = c_callback; // always the same function for the wrapper
my.eventuserdata = python_callback;


Hm... Well, I could use a skill in this case but that´s not very elegant and I would have to warn every user of the wrapper with "NEVER USE SKILL100 YOURSELF!" or something. smile