I am running the Marketpress plugin and it's really cool!

Hi,
I am running the Marketpress plugin and it's really cool! I have WP in MultiSite mode and marketpress with several user stores. As soon as a store owner is logged in, I would like to display two links in the header: One targeting the main site, one targeting the users store.
I did not find a solution for this.
Can this be done easily?
Marc