Asymmetric gain/loss analysis with a two asset portfolio and leverage

Hi,

I am stumped. Basically my boss wants me to show (graphically) that if I use x (say 10%) amount of leverage in a two asset portfolio (equity & debt) that there is asymmetric upside versus a pure equity portfolio and no leverage. Example data is as follows: Equity Return - 12%, Stdev - 20% and Debt Return: 5%, Stdev - 5%. The cost of debt is 2% so net debt is actually 3%. I am thinking I have to show that if the market moves up x% I would gain more upside than if the market moves down x% this is due to the leverage being used to purchase safer debt securities. I know this is a somewhat detailed request, but I thought the collective brains on this site might be able to help me build something in excel that would do the trick.

Thanks in advance!

Anyone, anyone? Help!