Hi Jayesh
It mostly depends on the purpose for the concentrator is currently configured over there.
If its configured for simple vpn tunnel between your locations then you can confiugre your ASA box accordingly and bring the tunnel up with your remote location during off peak hours.
if your concentrator has been configured for any other specific purpose then you can configure your ASA device accordingly and try to simulate the same kinda setup locally there with your box by doing so you can make sure you are not left with surprise issues later on once you take off the concentrator from the network..
regds
