Handling a window

Summary:
When we issue a print command to a window, the very first thing that appears is a selection window named 'Print' in which we select the printer that we want to use.(I'm using a Virtual printer) After pressing the 'Enter' key we get another window called 'Print to File' where we give the name of the file (path and extention) that will be printed. Pressing 'Enter' again will start the printing operation.

For my application I don't want these windows to appear,in fact the printing operation should appear to be occuring in the background. One 'dirty' technique that I used was to forcefully execute keyboard commands (programatically) whenever these window appear and hence cause a printout to occur.
But this method has its drawback...in fast PC's you will notice a faint flicker while in slower PCs it is quite evident.
I don't want to go into the driver level development of a printer (b'coz although that is a solution,it is not feasible for me right now)
Can somebody suggest a better technique that will virtually hide the windows and hence not cause any flickering?

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