Sure.
First, go to Firewall then Zones tab.
Make sure your network adapter (the line with entry type=network) is in the internet zone - not trusted.
If you have other machines on your local lan, you can add their address or machine name and assign them to the trusted zone here.
Localhost should also be assigned to trusted.
Add the VPN server ip address here and assign it to trusted zone also.
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Now go to program control part of the software, then programs tab.
For the two programs you like to connect only through VPN, make sure that only the Access/Trusted column has a green check. Make sure Access/Internet has a red x and also the two server parts have a red x.
Set like this, it will be impossible for those two programs to do any networking at all, except to the trusted zone....and you already added the VPN server to trusted....so this is great.
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If you need any other help with configuring, not a problem...