Placing php code in flyout box

Hi Marcin

Amazing plugin, thanks a lot! Work perfectly for me. Only one change – I want to place certain php code into box. So I want to replace ALL content inside your flyout box with my html/php code. I can not place it in functions file. And I don’t know how to make plugin (http://upprev.com/is-there-a-way-i-can-use-non-post-content-in-this-plugin.html). What would be the easiest option for me?
Please help and please consider I am noob in WP and not developer at all. I can deal with some basic html/css. That’s all.
Is it possible for me to hardcode somehow html box with my css and php code inside?

Thanks
Dean

http://ww.wp.xz.cn/extend/plugins/upprev/