Redmine

Hi everyone, I have a problem need your help here.

redmine version: bitnami-redmine-2.5.1-1-windows-installer.exe
Our company have two network, one is external network(59.57.176.xx), one is internal network.(192.168.1.xx) .
Normally there's only one web address link into the problem. Now we want to add an internal link into email notifiaction like below:

task#4249: xxxx
http://59.57.176.26:9180/redmine/issues/4249#change-127341 (external)
http://192.168.1.5:9180/redmine/issues/4249#change-12734 (internal)

Author: Cai Ling Ying
    Status: Closed
    Priority: Low
    Assigned to:
    Category:
    Target version: Project Management and Strategy

So others can access the link through the internal network instead of external network. Is there a simple way to make it? Thank you very much.