Using Asset management to keep track of rent

Hello,

My company just upgraded to Altiris Asset Management Suit 7.1

We are currently using two systems to keep track of all the Asset, the price, and the rental cost.

The IT department rents out the assets to other departments and we wanted to use Altiris to keep track of all that.
So here's the question: How do I register the price that we buy the asset at, and how do I add the rental cost for other departments?
It's not in the template for new asset.

Thanks,

Elísa