regarding window id

[Jyothi <jyothi ncoretech com>]

Hi,

    I have a toolbar . I have two buttons on it. when I click on one of
them, it opens an application .
when I click on the other , I should get the window id of previously
opened application. I don't have the grip on the application source code
so I can't use source code of the application to get the window id.

    Actually when I click on one button, I just use "system" command to
run an exectuable. When I click on another button, I should get the
window Id of the executable or widget reference of the executable .

    How can I get this window Id ???

Thanks in advance,
Jyothi.