How to host main domain (like whmcs) on another server without changing Cwp name

[fivestar047]

My domain example.com
My cwp name server ns1.example.com ns2.example.com
How to host main domain (like whmcs) on another server without changing Cwp name server

[fivestar047]

  Please help me

[cyberspace]

As I understand you want to make access to your billing (WHMCS) through the URL like:

whmcs.example.com

Right ?

If so then create the virtual host/account with the domain name/subdomain whmcs.example.com on your other server then edit the DNS zone of example.com on your primary server and add the DNS record like:

Name: whmcs.example.com.
Type: A
Destination: xxx.xxx.xxx.xxx

where xxx.xxx.xxx.xxx is the IP address used by whmcs.example.com on your second server.