Method call from query string of notifications

Hi,

I'm sending mails using inbuilt notifications on workflow activities.

I need to include the workflow history report in the mail content.

I could fetch the history report by giving an explicit call to the method - workflow history report (or a similar custom method which will return the HTML report content in a string format), but not getting how I can give a method call from within the query string of notification.

Is it really possible to do it this way?

Thanks in advance.