QUOTE(radio_cascara @ Aug 1 2007, 11:40)

thanks foosion, can you tell me if coding for dynamic tags involves huge amount of work, 'cos if not i just might bug developers to implement them

It's just as difficult (or easy) as reacting to normal playback events. If any developer has questions regarding the technical details, they should post in the development forum.
QUOTE(radio_cascara @ Aug 1 2007, 11:40)

anyway, i gather your answer also means there are no global variables or any other way i could transfer data between plugins?
The simple answer is no. Read below for the complete answer.
The foobar2000 SDK does not define a means by which titleformat scripts (possibly even from different components) can exchange data. There are some third-party approaches to this (in Columns UI and Panels UI), but as this goes beyond the intended scope of the titleformat language, none of those have been adopted in the official SDK.