How to use different DNS

Hi guys, 

i need help for this problem.

Network 192.168.1.0/24

Windows 2016 domain, 1 DC (DNS Server, DHCP Server, File Server)

About 20 clients in the domain, with the only primary DNS specified (the DC Server)

1 gateway with adsl provider XX to use for internet for 18 of 20 clients. The DNS Servers of this provider are set in the DC Server DNS configuration.

1 gateway with adsl provider YY to use for internet and for a specified program for 2 of 20 clients.

This 2 clients need to use the gateway YY and relative DNS, otherwise the software does not work.

I know i can set a different gateway on this 2 pc's, but i cant't set different dns, otherwise I would have problems with the domain.

So, Can I solve this problem with the 60d firewall installed on the network?

I thank you in advance for your answers.

Fabio.