reusing function

Hi

I would like to use this module but instead (or together with) pmgrowl popup box.
I would like to show info about new privatemsg in my statusbar on the top of the page. (the same system as in facebook, statusbar can be cached, and number of new messages is getting by ajax).

so can you please help me, is there is some function/hook which is simple to modifield, for adding number of new messages into some html code? I suppose that there could be just added together / or replaced the code where jgrowl popup message is shown.

thanks a lot
Igor