Hi Pontic,
Pete replied on the following thread on the subject:
http://www.specialist-military-publishing.co.uk... Only one +1 or action per command unit. Your recces will basically communcate with the closest unsuppressed command unit that hasn't been in a succesfull communication with a recce yet.
As Leonardo says recces use the closest enemy unit concealed or not.
Pete excludes enemy command units from the possible recce targets in the thread I linked to. But our group uses a house rule where you choose whether you want to use the enemy command unit as the target unit or use the closest non-command unit. This way you need to pay a price for pushing the command units at the front of your troops too much. But you still can't fire at enemy command units even this way. If the enemy command unit is the target of the recce the only possible option is the +1CV benefit.
BR,
iA