To Forward a “page” to a subdomain help!!

Hi! i need help, i have my main blog on mydomain.com but i create some subdomains like photos.mydomain.com So i would like that when people click on the tag “Photos” they will be sent -forward directly- to photos.mydomain.com instead of going to
mydomain.com/photos sorry im newbie!!! : (

for example, How to change page “about”, so when people click there -about- they will be visiting the subdomain about.mydomain.com where i did a simple non-wordpress webstite.

thanks!