Capture Visual Features with JRex

Hi every body,
I am new user of JRex. I want to capture box models positions of tags in the 
DOM tree of arenderd web page using JRex. I mean by box models of a tag, its 
position in the rendred page. Example, the tab <P> will be rendered at 
position row (15 pixels) and columns row (20 pixels). Is it possible with JRex?
Thx.