Display MarketPress Global Store on its Own Blog

I've created a blog called globalstore and I'd like to have all other stores on my site aggregating their content there, rather than on the root blog - as is the default setting for use of MarketPress.

I've posted about this in another thread, but I think it got lost because my question was initially related to doing the same for Membership and classifieds as well.

So. Ive posted again, but as a single request.

The previous comment from Aaron was:

Just change the code that checks for the main blog to check for a different blogid

Can more detail on this can be provided in regards to which file and line in the code needs to be changed.

thanks
Paul