I've done some things this kind when I began to play with RabidVWM. At the begining, RabidVWM was buggy in a fine way:
VWMOnMoveWindow !VarSet WinTitle "^@wt^"
...used to be called on every focus change. Now, it has been fixed and you couldn't use it anymore for knowing the active window.

But you still could use a timer and VWMExec to ALWAYS know everything you want about the active window:

Then, you can do things like:
!Exec !VWMExec !One "^@wc (#h %{WinHandle})^" "^@wt (#h %{WinHandle})^"