you said that the message is sent from another application? so are the two applications Qt applications? If yes then take a look at QtSingleApplication class (its a solution from troll). what they have done is that they send message to other application which is caught in some function(slot may be).

so the point is that somehow you land up in your application's function.. in that.. you can experiment with first setting the windowOnTop flast and then reseting. ..

i dont remeber QtSingleApplication code so this info may not be correct.