i have to sites inside my network
192.168.1.12 on ssp.domain.com
and 2nd one 192.168.1.15 on ggm.domain.com

i want to publish both on same public ip but the header is different ?
public ip is xx.xx.xx.xx
can i do it?

it's possible using Web-Proxy, but your sites will see only your router's IP instead of IPs of external clients (but maybe you may use 'X-HTTP-FORWARDED-FOR' in proxy headers, didn't tested...)

great but how to do it in webproxy

add their internal addresses to DNS and redirect all external requests to your proxy

great , i'll test and let you know