need advise about pptp server mikrotik?

Hi all, need some advise about configuration pptp server mikrotik, i setup pptp server mikrotik for clients wants to access application program
on windows server, the problem is everytime clients vpn connect to apllication program via vpn mikrotik at same time one user/client will be kicked out from application program. I ran packet capture on pc application program to test out when the 2 users client vpn try to connect application program and when i see the results i realize something and see that connections is come only from the gateway (which is 192.168.0.1) its different on local network when other local client access the ip came from the original ip network i assign .
Is there a way to have pptp conf so the client have direct communicattion to some ip address in my local network ? cause from packet capture i saw is the vpn clients connection read as from 1 source ip (via gateway ip ), could it because nat conf

chain=srcnat action=masquerade src-address=192.168.0.0/24

need advise about this issue, please?

the gateway mikrotik ip is 192.168.0.1
ip application program(win 2000 server) 192.168.0.43(assign from dhcp server mikrotik)
the pptp client ip for user1(local address=192.168.0.126, remote address=192.168.0.127)
the pptp client ip for user2(local address=192.168.0.122, remote address=192.168.0.123)
the clients vpn using windows xp.