Createprocess and set the window position

[Super Hornet]

Using createprocess I am invoking a dialog based application and from the processid I am getting the HWND of the dailog and then setting the window position, till now it's fine. The problem comes when we try to invoke a dialog based application(using create process) which has an error in initializing(displays warning or error message)after pressing ok on error message the dialog is invoked for which we are unable to setwindow position because of error message. How can we by-pass the error message and set the position of dialog??? Note: We do not have code for invoked process.