Force www on a subdirectory

Hi i have a site with subdirectories

The main one is mysite.com and i have the "force www" code on the main domain so it changes to http://www.mysite.com

I have a sub directory, mysite.com/page1 and i would like a htaccess code to "force www" on my sub directory and everything inside it.

For example:

mysite.com/page1
Would be changed to http://www.mysite.com/page1

And everything else in the "page1" subdirectory gets forced with "www"

Example: mysite.com/page1/forum.php
Would change to: http://www.mysite.com/page1/forum.php


Thanks in advance

RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/page1/$1 [R=301,L] ?

Where do i Insert my domain in that code?

Amd
I want the "force www" only to work when someone types: mysite.com/page1

If they type www.mysite.com/page1 Then it shouldnt redirect

help????

Anyone help??

Did you try abduraooft's code? You don't have to enter your domain because he used %{HTTP_HOST}, which is the requested domain.