PHP & MySql database update

[invidious]

I have a discussion forum that is currantly running in perl. I am going to move it over to a php and mysql based forum. The new forum runs perfectly, and I can import all the previous user information and the previous posts. The problem is, that in some of the posts there are links to other threads on the board. After importing the posts, these url's no longer function. I need to make a script that will do the following:

1) Search for all occurences of
"

http://www.url.com/noncgi/forum

[##]/html/[old id].html"
2) Search for the new threadid, based on the old id
3) Replace the string in #1 with
"

http://www.url.com/showthread.php?threadid=

[threadid]"

The old id is being stored in mysql during the import on the same row as the new threadid that is generated for that post.

Any suggestions? [sig][/sig]