Can I send a message/command from a Qt application to an another like in MFC?

In MFC, I use ::FindWindow() and ::SendMessage() to send a message/command from a application to an another. But I don't know how to do that in Qt. I read about QProcess but I didn't find out any similar solution.
Can someone help me solve this problem?
Thanks for reading!

Use regular WinAPI calls for that (Find Window and SendMessage/PostMessage). And yes, these are not MFC calls, but WinAPI ones.

Thanks wysota, you're right but I have to develop an application on both Windows and Mac OS X and I don't know about Mac as well as Carbon environment very much.

Posting messages to other windows is platform dependent. Use some independent mechanism instead (like sockets).