parsing variables to an external file

[ageurtse]

Hello,

i'm in the process of building a plugin, with this plugin there is a post button which calls a external php file.

now i wan't have acces to all the variables that are present at that time.
for instance user name, thread id and so on. there are also some custom variables.

how can i use them in my custom php file.
i don't want use file.php?someinfo=info

i will only call file.php and all the info should be availeble in file.php

how can i do this.