Hi Peperez,
Just create a new entry in your airbase.dat file. "located in your CFS2/info folder"
Change the red XXXX's to match the next airfiled in your list. It won't show up in freeflight but you can use in in missions. For it to show in freeflight you will need to make an ADF.bgl.
[runway.XXXX]
id=xxxx
name=Henderson Seabase
heading=322
allegiance=0
units_across=2
base_lat=S 9* 25.12'
base_lon=E 160* 4.65'
base_alt=0
takeoff_start_pos=-600,0
takeoff_stop_pos=1600,200
landing_start_pos=5000,350
landing_touchdown_pos=600,0
landing_stop_pos=-250,0
Hope this helps,
B24Guy