How to make "custom hint action"

I want to make plugin to work like this:

lets have a code:

int a = GetNumber();


there is some expression. I want to write some provider which hooks on
when mouse is over some "element' to provide my custom action, like
show Hint Window with some custom information.

I found how to show hint window with custom text (new
TooltipInfo(....)) but i want to know from which interface(and where to
register) my class to be hooked on "mouse over" on some editor
text/expression. Is this possible with R# 2.5.2 or not?

--
Peter Sulek
terrorix@centrum.sk
XanaNews ver. 1.18.1.6