[TYPO3] Dynamic data - typoscript question

[Stig Nørgaard Færch]

I have some typoscript like this:
30 = IMAGE
30.file = GIFBUILDER
30.file.XY = 121,200
30.file.backColor = green
30.file.10 = BOX
30.file.10 {
   dimensions = 0,120,121,80
   color = black
}

I would like to change the dimensions part dynamically - based on data 
from the database etc.
I know that I can use constants to input other values - but I guess this 
doesn't solve my problem.
Is it possible at all?

Thanks in advance!

/Stig