?how do I amortize leasing commission expense over the term of lease on my rental property. Versus taking it as a one time expense.

You need to use the asset entry option where you will see a screen that says Describe This Asset. Choose the Intangibles, Other property option. On the next screen choose Amortizable Intangibles. In the next screens you can enter a description and amount for the amortization and choose the amortization period.