burndown chart for development tasks only

I imagine this question has been asked before, so please forgive me.

I have a slew of tasks, a bunch of which are development related (code, junit, design, etc.), and another bunch that is testing related. The development tasks are Filed Against Development, and the testing tasks are Filed Against Testing. However, we only have one Team Area defined in RTC, for all developers and testers.

Now, the canned Burndown report takes into account all of the tasks, both development and testing. However, I'd like to create/see a Burndown chart that is built using the development tasks only. Seems like I should be able to somehow tell RTC to create a Burndown chart using only the development tasks. Can I somehow create the chart using the Filed Against Development tasks only?

Looking at some previous posts, I'm thinking I may need to create a sub-team of developers. Help!