Hi,
Sure, it is possible as both Virtuemart and our template are open-source. But it would require hard-coding in the CleanMart files.
What you are asking is 100% custom modification
(because you want to change how things function or look). Unfortunately we don't provide free-support or step by-step instructions for custom coding modifications.
You may purchase premium support:
www.flexiblewebdesign.com/premium-support
and let us take care this customization for you directly on your website though.
Regards.
Support