File Handle Resource

Now that the list is back up, I have a question... In my module I'm writing, I need to have some functions that will take as an argument a FILE resource id. So the question begs asking is there any function I can call to obtain the FILE resource structure (that contains the FILE*) from the standard file module? In my module, I don't want to have to modify the File code, or make some variable global or anything. I just want the user to give me the File resource, let me call a function that will give me the structure to the open FILE *. Does that exist? Any other suggestions? Brian