madal dialog and modeless dialog problem

hey, guys!
I have some problem about dialog.
I need your help.. please help me!

I wanna my dialog not showing window task bar, application only can be show..

If I made some dialog ( modal, modeless, anything), I can show dialog in task bar.
at that time, I'm not set dialog's parent.
so I set parent of dialog. but at that time, dialog can not move out of application!
It present modal and modeless same.

What do I can create dialog that not showing task bar and moving out of application?

I mean I want make dialog similar fileopendialog.
fileopen dialog can move out of application, and not showing window task bar.

fileopendialog is modal dialog but I want modeless dialog, too.

Please help me!
any hint??