.htaccess redirect from sub.domain1.com to sub.domain2.com

[echoniner]

I am really struggling with this problem, and have tried every thing I can think of in my limited .htaccess knowledge to make this work:

I want to redirect every call to any page from one subdomain.domain.com to another, with variable parameters.

For instance, I want

http://subdomain.olddomain.com/index.php?many_variables_here

to permanently redirect to (with the addressbar in the browser reflecting the new)

http://subdomain.NEWdomain.com/index.php?many_variables_here

I'm redirecting one subdomain only to the same subdomain name at another domain (permanently...want all expired links to still work). That is, www.olddomain.com still exists and is not to redirected, just subdomain.olddomain.com is to redirect.

For what it's worth: olddomain is an add-on domain of newdomain.

Thanks!

[echoniner]

I put the following into a htaccess at FILEPATH public_html/sub/ :

RewriteEngine on
#
RewriteCond %{HTTP_HOST} ^(www\.)?mydomain\.com [NC]
RewriteRule ^(.*)$ http://sub.mydomain.com/$1 [R=301,L]

It seems both worked for me only on condition that I change the last line to be ^(.*)$ instead of ^sub/(.*)$

any idea why? (but it works, just want to learn)

fyi: I'm not being selective: I want no links whatsoever to be to mydomain.com/sub/xyz

Jim... you are a true expert! thanks again for everything!

[echoniner]

thought I'd ping this...

Happy Thanksgiving all!

[edited by: jdMorgan at 10:09 pm (utc) on Nov 30, 2010]
[edit reason] Removed duplicate-post explosion [/edit]

[jdMorgan]

Because the path to the current directory is removed from the URL-paths 'seen' by RewriteRules in the .htaccess file in that directory. The URL-path examined by RewriteRule is 'localized' to the current directory in other words...

Jim

[echoniner]

Ah, I get it. Thank you again so very much! Happy holidays!