Dear corsica Iwan :)
For the moment you can Hide, Invert selection, and for this one "hide invert selection" by script
(give me some minutes for refound it) Yes you can add scripts in this marvelous prog!

@Iwan
Ok that was that
Just copy this (or part of this folowing whish) in the "Moi.ini" in the /Application Data, i don't know where it on your comput as Windows is a real "foutoir" :D
Of "corse" :) script is by Michael, not by me !

[Shortcut Keys]
Ctrl+A=script:moi.geometryDatabase.selectAll();
Ctrl+C=CopyClipboard
Ctrl+N=New
Ctrl+O=Open
Ctrl+S=Save
Ctrl+V=Paste
Ctrl+X=Cut
Ctrl+Y=script:moi.command.redo();
Ctrl+Z=script:moi.command.undo();
Delete=Delete
E=Extrude
F1=script:moi.launchHelp();
F11=FullScreen.js
H=script:moi.geometryDatabase.invertSelection(); moi.geometryDatabase.hide(); moi.geometryDatabase.selectAll();
I=script:moi.geometryDatabase.invertSelection();
R=Rotate
Space=script:var selection = moi.geometryDatabase.getSelectedObjects(); if ( selection.length == 0 ) moi.geometryDatabase.selectAll(); else moi.geometryDatabase.deselectAll();

Have fun with moi and don't kill to much wild piggies whith your knife :D