Modding cannot alter the game mechanics, it can only alter the units/items/spells stats and chose different 'hardcoded' functions for them. (Btw., this is pretty obvious from the modding manual...)
A "move and search" funktion is not possible without substantial changes to the game engine: "search" is a monthly order, while "patrol" is a state. "move and patrol" lets the unit move, then set it to "patrol" - which will carry over to the next month. "search" cannot carry over, because its a monthly order like movement. There can't be 2 monthly orders anyway ... .
If that was easily possible, we would have movement along waypoints or at least over 2 turns (to a distant target) for a long time.
At least that's what I have deduced from seeing how the game works and some of the devs comments. Maybe I'm all wrong and Johan is simply lazy ...
Btw., I have done some programming at University 17 years ago - using Fortran77. Anyone who remembers that language?