Changing Video timings in omapfb

I would like to change my video output for my specific output,

I have fallowed some other posts and was able to set my monitor to
800x600 by:

setenv dvimode 800x600MR-16@60 in uboot.

But I need to be able to change my timings to:

Pixclock=42503
left=48
right=156
upper=1
lower=30
hslen=114
vslen=3
Vertical Sync = Low
Horizontal Sync = high

Ive tried using commas to separate the properties like:
   setenv dvimode 800x600MR-16@60,pixclock=42503,vsync=low,left=48...
but no luck, according to fbset it still is set to 800x600-61 with
all of the default timings.

I have tried to run fbset on the properties but I dont notice a
change, ive read you cannot change properties with fbset on the fly.

Is there anyway to set the timings to not a default value in the boot
args?

Thanks