subdomain pointing over .htaccess

[etterra]

Hello,

On my hosting I'm able to setup subdomains that are directed to a folder with the same name of the subdomain:
-> test1.mydomain.com ->> mydomain.com/test1

My hosting company doesn't let me change the folder in the admin panel.


Now I have a vBulletin Board running in the place: mydomain.com/forum and I would like that the subdomain points to the forum like this:

-> test1.mydomain.com/forum

So when a user selects the domain: test1.mydomain.com he should see the /forum/index.php and be able to access the entire forum and in the domain line in the browser there should be the subdomain itself.. not the original domain.

I tried to do that with a .htaccess file.. but I couldn't bring it do work. Can you help me with this?


Goal: I would like to set up three subdomains and each subdomaind points to the forum directory. Then I would like to make a different template for each Subdomain that is being pulled depending on the domainname.. seen here:
https://vborg.vbsupport.ru/show...=style+multiple

I've spent more than 10 hours trying to figuer out how to do this but I'm not getting any further. I would be very happy for any help.


Kind regs, etterra