AppleEvents and GraphicConverter

At the very end of GraphicConverter's Manual it tells you how to 
convert graphic files from one format to another. Based on that 
'recipe' the following AEBuild (surprisingly enough) works:

	$evt = AEBuildAppleEvent(
	    'gcSt','xCnf', 'sign', 'GKON', 0, 0,
	    qq(
	    	kysc:TEXT(\@),
	    	kytg:TEXT(\@),
	        kywf:1
	     ), $source, $target
	) or die $^E;

where $source and $target are full-path file-names.

However I simply cannot find an event 'xCnf' of class 'gcSt' nor any 
of the keys anywhere in the GraphicConverter 'aete' resource. Can 
anyone shed any light on this?

A frustration with the script is that it opens a window while the 
conversion goes on, although nothing is actually drawn in the window. 
Can anyone suggest a way of stopping the window being drawn or 
drawing it off-screen or something?

A mouse-driven conversion after all opens no windows, so one feels it 
should be possible to do a 'windowless conversion' by AE methods too.

I hope this is not too far OT, but it would be very useful to be able 
to convert 'gif' and 'jpeg' files to 'pict' format, on the fly and 
behind the scenes, so that MacPerl can draw them in a MacWindow. The 
end use is Toolbox related even if the question isn't.

Alan Fry