I think (this might help you with how to code it Zup) that the squad wars server would be a new server, and when a squad member entered it they were automatically put in with anyone else from their squad...but always on the same team or there could be an option when choosing planes for the pilot to choose whether to go with or against their own squad.
I'm not sure what language you use to code Zup, but here is a general idea, in basic coding
Getsquad(meaning find out which squad)
getsquad set (variable)
display option to chose for/against (not sure how to code this part in anything other than calculator (TI 84) basic
if (variable) = (reference stored library of squad variables already in games)
then (puts pilot in that game)
determine side to be placed on (again, not sure of coding but here is a shot at it)
get variable (this would be determined by the option the pilot chose)
if var(option to be put against squad)*var (of squadron) is found in library
and var(option to be put with squad)*var(of squad) is also found
then
put on either side
else
if var(option to be against squad)*var(squad) is not found
(this is all just putting on side with/against enemy...im gonna stop here but it would go on a bit, determining the side to put the pilot on) basically, if there are no other pilots wanting to go against their squad, put the one that wants to go against on other team, if there are both for and against pilots, put the pilot on either team
not sure if this will be of any help to you zup, but I hope at least the idea of the code I wrote and the general function of it will help give you some ideas!