photo.tpl how to get the item number for use on a php script

Hi i was just wondering if anyone could help.
Hopefully i have posted in the correct forum!

The problem i am having is that i have created my own php script to use within gallery 2 to create a custom next, back, and random image.

Is there a way, in the 'matrix' theme 'photo.tpl' to get/set a variable in php that is from the current image?

So if im on photo id 250 .... i can say (in php)

$thecurrentpagenumber = ?????????
/// now do something with the page number

If anyone can help it would be much apreciated.

Regards

Alan