Look at this:
onMapSingleClick command
Operand types:
command: String
Compatibility:
Version 1.85 required.
Type of returned value:
Nothing
Description:
Define action performed when user clicks in map. Command receives:
_pos array position
_units array selected units
_shift,_alt bool key state
If click is processed, command should return true.
Example:
onMapSingleClick {"SoldierWB" createUnit [_pos,group player];true}
_units is the one you're asking for
So basically the array you're talking about exists.
But i'm not sure, wether it's possible to access those selected
units without summit special like the onMapSingleClick.
(haven't tried or needed that yet).
~S~ CD