Well, I asked to the AI and IT gaves me some tips.
Add the entries below on XXXX_Targets.ini
[TargetArea023]
Name=Torokina Field <------ your base name
Position=927000.00,1257000.00
Alignment=FRIENDLY
Location=1 <----------------check location on terrain XXXXX_NATIONS.ini
AirfieldDataFile=desert_airfield1.ini < -------- use the right one for your base - "1" for SMALL, "2" for MEDIUM and "3" for LARGE
ActiveYear=0 < ---- If I understand correctly, is better to leave as 0 (zero) to avoid any mess with other dates.
Radius=6000.000
NumSquadrons=4
BaseMoveChance=0 < -------------THIS NEW LINE MUST BE ADDED
OpenBases=Torokina Field < -------------- THIS NEW LINE MUST BE ADDED WITH THE SAME BASE NAME
Target[001].Type=USMCstripRunway ... and so on
Make this changes to ALL USMC bases, in other words, the same NATION of your plane.