Not quite sure what you're after but I'll have a stab, this might not be the answer but hopefully it'll nudge you in the right direction.
If you have a group that might need backup if you name the leader:
L1
Insert a trigger with:
("alive _x" count (units l1)) < 4
in the "condition" line.
In the "On activation" line put:
L1 sideChat "Need backup"
This will get your squad to report they need back up when their numbers are less than 4.
If you want to get fancy there may well be ways of putting L1's co-ordinates in the message but that is beyond a quick answer and me.
Chances are you'll need to use some scripting.
Alternatively you could use Bremmers AI script (search at the editors depot) on the players squad and the squads that you want tracking and it'll do it for you, kind of.