Hi,
I have absolute no idea what you are talking about.
But what you are asking doesn't look an easy thing to resolve. Before providing you any solution, I would need to run some tests in my server, it means; i need to spend some time on it which i don't have any these days. I barely find a chance to answer support questions to resolve bugs, but custom coding changes questiond are definitely beyond our free support.
Did you try to open a thread in
forum.virtuemart.net ?
I am sure someone will help you out there.
Cheers.
Support & Development