replace part of an url

[raffael3d]

I have a column in my database whcih contains an url. this url is displayed on a page. Now I want to display it on another page. but this time a part of the url has to be changed.
here an example:

first url) www.yourdomain/help/index.php

now I want to change it to www.yourdomain/special/index.php

so Is there a way how I can retreive a entered url from the database and change a part of it? what always is the same is the fist part: www.yourdomain is always the same.

is there any way how I can do that? Don't tell me please that I should change it when the data is inserted into the database. it's too late, the database is very big already.

thanks

[RoadKingHD]

You could use a regular expression in MySql (if you use MySQL) and replace parts of the URL or you could loop the data pulled from the database and use eregi_replace() to alter the url in PHP.