I think you need to be more specific. What do you mean "won't work"?
But, if you need to read the PHP into the file, and then parse the PHP (then somehow print that into the PHP code area?), do this.
Read the file into a string, then eval the string. You may have to strip off the <?php and ?> tags.
I think you need to use fread to read the file into a string. I kinda forget.