VPN using PPTP (IP dosent change)

Mikrotik RB941-2nD-TC hAP Lite
Hi
I have connected my Mikrotik Router to my TPLINK ADSL Router
through LAN Port.
Internet is working fine on Mikrotik Router.
On Mikrotik router, I have setup VPN using pptp-client
and it connects Sucessfully.

if any hosts connects to Mikrotik Router..
My Internet IP dosent change to VPN IP what should i do ?
Please guide me.
Here are the details

Host:
My ip : 192.168.88.254
My Gateway : 192.168.88.1 (Mikrotik Router)

VPN Server name : 141.101.161.2 (to which i connect)
pptp-client (After connecting to VPN Server i get..)
local ip : 141.101.161.11
remote ip : 141.101.161.5

Inside Mikrotik Router:
Route list
DAC 141.101.161.5 (dst.addr), pptp-out1 reachable (gateway), 141.101.161.11 (Pref. Source)
DAC 191.168.1.0/24 (dst.addr), ether1 reachable (gateway), 192.168.1.100 (Pref.Source)
DAC 192.168.88.0/24 (dst.addr), bridge reachable (gateway), 192.168.88.1 (Pref. Source)

Address List
D 141.101.161.11 (Address), 141.101.161.5 (Network), pptp-out1 (Interface)
D 192.168.1.100/24 (Address), 192.168.1.0 (Network), ether1 (Interface)
defconf
192.168.88.1/24 (Address), 192.168.88.0 (Network), ether2-master (Interface)

i know how to setup Mangle Rule in firewall with mark routing
and i know how to define Default Gateway 0.0.0.0 with defined mark routing
but i dont know where what to put.
Please let me know about any other settings..

Please Guide me thank you
regards, DigitalSoul.