Local pptp vpn real ip

Hi

We have local pptp server (mikrotik) for our local users to connect to the internet in our company. We use a pool on mikrotik for local pptp connections and NAT their pool ip for internet access. I want to find a way to see local users with their local ip address not ip from local mikrotik pool. The main reason for that is I have IDS and it does not see the users local address.