You can send a pointer to the main dialog into the newly created thread. This way you can "visit" it from within the second dialog.
>>And I also tried to post some messages to the thread based dialog from main dialog but no way was found.
How did you do this? You'll need a handle to the dialog to be able to send messages to it, don't you?
If all you want is communication between the two dialogs, I would suggest you send in a pointer to the main dialog when creating the second thread. Then, from the second thread, send in a pointer to the second dialog by creating some method called "Set2ndDlgPtr" or something like that....
Greetings,
Rick