To elaborate a little on what Erik said, I'd try a post processing command object (under the Solution branch) with commands like these:
Where contact_surfaces is a named component (the surfaces on both sides of the contact interface) that needs to be created before running the command object (it's possible that the model may first require a resolve after creating the named component).
The gap results should appear on file "gap.txt" and the pressure results on "pres.txt". Both files should be in the MECH directory several levels down from the directory to which the project has been saved. Please note that I haven't tested the APDL above... if it doesn't work it probably doesn't need much further modification to do so.
For more details, please try to locate and review the Mechanical APDL Help articles shown in the screen shots below: