need some help please

[Stu]

I've written a PHP script (unread.php) that collects some info from vB and my mail program. It stores this information in a variable called $unreadmail
If I run the script it collects the information and echo's it from the $unreadmail variable

I'd like to be able to place the variable anywhere in the vB templates, probably Postbit.

My question is what is the best way to go about making this variable available.

I'm assuming I'll need a line something like this
require("http://www.mydomain.com/unread.php");

is that correct? where should I put the line? and how do I make the variable global.

Thanks in advance for any help you can throw my way.