Configure the connections from a local VPN to an external VPN

I have a local server with this LAN ip: [login to view URL] (eth0) The local server connects to a VPN with FortiClient (external VPN) with PPP (ppp0), info: inet addr:10.10.50.101P-t-P:1.1.1.1 Mask:[login to view URL] The local server has access to different services through the forticlient VPN, for example: [login to view URL] port 3690 [login to view URL] port 50000 The local server has its own PPP vpn service, with local ip [login to view URL] Once a client (or clients) connects to the local VPN, the client gets an ip [login to view URL], 6, 7 and so on (ppp1, ppp2, etc.) I need the client (from local VPN) to be able to connect to the services available in FortiClient VPN (the external VPN), either by using the same IP ([login to view URL] or 175), or with a translated ip: FortiClient IP: [login to view URL] = Local VPN: [login to view URL] FortiClient IP: [login to view URL] = Local VPN: [login to view URL] I need the solution with comments about what was made.