In Pro/E, the dimensions in the drawing will appear as you have created in the sketch while creating the model. So while creating the model-in sketch you create the dimensions as you want to appear in drawing. Then in Drawing, use Show/Erase to show the dimensions that you made use of.
Create Dimension-Ordinate-Create Bases-Click on a dimension and then select a base - in your case a right vertical edge or so. Then Create Dimension-Ordinate-Create Dims-Click on 0(zero) and then the required edge to dimension. That's it.