catch event from other running app

[Krzysztof Gorzelak]

Hi,

I'm looking for a way to customize an existing application by adding
some additional code on top of the running app. I would like to catch
some events (like double click on text field) from an application
(running binary on win32) and attach an extra external vbs code. I
understand that I won't be able to access application internal
variables, but I would like just to perform some actions (web query)
based on text fields available from the interface.

Thanks
KG