I'm from Argentina, but I'm not sure I understand exactly what it is that you need.
These are the ways to buy BTC with Arg. pesos:
+
Virwox using your CC or Paypal (you buy in USD and pay Pesos to VISA/MC/etc.)
+ Local Bitcoins
+ Act as exchange for a tourist coming to Argentina (he gives you USD/EUR and you give him Pesos to use during his stay; he avoids getting scammed at black market/airport exchange (yes! they scam over here)).
+ Buy from someone in the forum whom you absolutely trust and willing to sell you through a service like Square or Paypal (so you can use your CC's and pay them in Pesos). For this to happen, he must really trust you given he is accepting a CC trade which can be abused in your favor.
Expect above average fees in all of the above.