changing ui win scale per .xml file?

[Dregostyr]

I was just wondering if any one knows a way to change the size of a ui window in side of the xml with out using /winscale in game.
For instance I am trying to find a way to make my reactions window/s smaller but keeping the rest of my windows the same. I am using the vguireactions.xml from darksteel, but I have it set into a mesh of other ui parts.
any suggestions would be nice thank you. if you would like the .xml code on here let me know and i'll post it