Challenging 301 redirect

I've posted this on a few other places, but I thought I could get some help from you guys as well.

Ok I have been looking on the internet for this answer but haven't found one. Here is the situation:

I have several domain names that all point to the same index file on my server. The file they point to is dynamic (index.php) Which serves different content based on what domain it is.

I would now like to do away with having multiple domains all pointing twards the same file and just redirect them to a master domain which will provide a sub folder for each domain pointing twards it.

Example:

Domain: http://www.bluewidget.com - 301 redirect to -> http://www.widget.com/blue

Domain: http://www.redwidget.com - 301 redirect to -> http://www.widget.com/red

*Just to remind you that http://www.bluewidget.com and http://www.redwidget.com both currently reference the same dynamic php file. And also, the sub folders (widget.com/blue) are already setup and ready to go. Its just the redirecting process im stuck on...

How can I do this redirect? some sort of mod re-write I beleive. Im just not sure on the exact code i need for the htaccess file

Thanks
Tony

With PHP + Apache:



Should work...