Here is something that may give a challenge.
Select your plotting area with a floating paper window that user can locate the desired center of this paper window. The size of this paper window would be based on the size of the paper selected and the desired scale. I picture using the default plotting dialog box so as that you can have all the default features of Autodesk. When opening selected the user will be taken to editor window in similar fashion as when the Window option. The user would see the outline of paper edge and can float it over the geometry until the user selects the desired center of this floating paper window. ACAD then would only plot what is inside the limits of the floating paper window.
We have in the Office a cad program called DrawBase. Anybody knows of it. IMHO, it lousy cad program that I had the misfortune of trying to learn. Basically, you had to turn logically cad thinking inside out then upside down. However in it defense there was few good attributes. One was this plotting feature.