can someone give me an example?

file_cpy("model.mdl","model.pak");

but when you dont know this, I think you dont have any .pak files anyway.

This is what happend at me:
i´ve renamed XT.wrs to XT.pak.
then created a script. file_cpy("ix_lalal.mdl","XT.pak");
then acknex copies the xt.pak data and renames it to ix_lalal.mdl(the name of the model)
how i can extract my model?
it only copies the XT.wrs.
it is very very very important.

I think you confused something. You must not rename the WRS file. Its name must be .wrs, otherwise you can't extract .pak files.

I guess the only way on your case is contacting support.