Exposure Compensation in Movie Mode - Aperture

I notice that with my Canon T2i when I'm in "movie mode" - if I use the exposure compensation function it wants to adjust only the shutter speed in order to lighten or darken the expsoure...I want the camera to leave my shutter speed alone and only adjust the APERTURE value when I'm applying exposure compensation.

Is there a way to do this with the Canon T2i?

If not, is this function available in higher end Canon HD DSLRs like the 7D or the 5DMII?

I can't find a menu setting to let me do this :-(