Access $post variables in external php

[CampinCarl]

okay. I'm writing a tiny widget for the post_legacy template that uses a players $post['field5'] (or their steam id for steam) information to make a html widget with they're associated stats. The only problem im running into is that i cant access the $post['field5'] from the php script that gets included in the template with a plugin.

Any help would be great.