Is it possible to deselect random elements? I know you can select random elements (verts, edges, etc.) however is it possible to deselect elements?

I want to be able to select random elements in a certain area (which would be defined by a preexisting selection)

I tried 


Selecting an area
Inverting the selection
Hiding the inverted selection
Selecting random elements
Unhiding


The only problem is the hidden elements are selected when they are shown again. It can sometimes be a pain to deselect these without affecting the randomly selected area.
After selecting your random vertices, assign them to a vertex group.  Then unhide everything, unselect everything.  Finally, select the vertex group.