Simple Interspire Marketer Adjustment

I'm looking for someone that is experienced with "Interspire Emailmarketer". Each e-mail can contain a %%unsubscribelink%% tag which inputs the unsubscribe link. However it always takes the host of where interspire was installed. I want to use it for different websites so i want to customize it so I can fill in the hostname like this: %%unsubscribelink:hostname%% -> it would look like this: %%unsubscribelink:www.freelancer.com%% - The output url would be http://www.freelancer.com/unsubscribe.php?etc. instead of the host where interspire is installed. That's the only thing that has to be done. Please only bid if you're experienced with interspire email marketer. Thank you for your time!