hi, how do i go about redirecting a subdomain to a variable

[ted_chou12]

Hi, I wish to redirect a subdomain to a variable, such that it turns:

test.domain.com => domain.com/?lan=test
test.domain.com/randompage.php => domain.com/randompage.php?lan=test
...

i am not very familiar with this mod, so i am not sure what is actually going to happen to a page that already has some variables like this one:

test.domain.com/rdp.php?user=123 => domain.com/rdp.php?user=123&lan=test

should this be the logical way of it or something else?

 

I have tried this so far:

RewriteCond %{HTTP_HOST} !^test\.domain\.com
RewriteRule (.*) http://domain.com [r=Permanent]

 

thanks!

Ted