Facing issue with IPsec, OpenVPN and Virtual IP

[akibsayyed]

I am setting up IPSec and OpenVPN combination in the following manner.

Part 1
1: I have Site 2 Site IPSec between my provider and me
2: In  first phase 2 I have a remote IP network with 10.0.0.96/27 for local network 10.0.2.10/32
3: In second Phase 2 I have the same remote IP Network 10.0.0.96/27  but a different IP 10.0.2.11/32
4 in 3rd Phase2 I have remote IP network with 0.0.0.0/0 with local network 10.0.2.12/32
below are routes
 for 1st phase2
IP 10.0.0.104 will communicate with 10.0.2.10
for 2nd phase2
IP IP 10.0.0.105 will communicate with 10.0.2.11
for 3rd Phase2
traffic from 10.0.2.12 will be sent to 0.0.0.0/0 network

now I configured all network and IPsec tunnel goes up

Part 2

I have setup openvpn client server
1: client 1 will have IP 10.0.99.10
2: client 2 will have IP 10.0.99.11
3 client 3 will have IP 10.0.99.12

I want to map IP in the following way
IP 10.0.2.10 will be mapped to 10.0.99.10 using virtual IP
IP 10.0.2.11 will be mapped to 10.0.99.11 using virtual IP
IP 10.0.2.12 will be mapped to 10.0.99.12 using virtual IP

I managed to do this partially means when I ping from 10.0.0.104  to 10.0.2.10 i do receive ICMP but when I send reply I fail to do this.

Please help