Bulk Re-Directs

I have a current shopping cart that I want to switch to another domain but I have some good results for certain pages in google so wat I want to do is setup up multiple 303 re-directs from a category and all the product pages but therre are so many that it will take forever doing it individually, does any one have a solution so that I can set up a re-direct in a category that will automatically forward all the subpages in that category. Hope this makes sense thanks in advance.
When we cancel the contract with the cms company we will move the domain that I think is uses a linux server but it doesn't actually say now you mention it but I will definetly give that a try thank you
I have been looking more into this now because we are ready to move the website but I have another question. This is the code to insert in the .htaccess file:
RewriteEngine on
RewriteBase /
RewriteRule ^old\.html$ new.html [R=301]

Where you specify the url you are re-directing from can you list a few there each with the spcific tags?
Hi Guys
Finally transferred the website over but I have run into a problem, the majority of the re-directs work (thanks for the help rgregory) although certain pages have not worked and I can see where I am going wrong. What I have done instead of listing every page is done a bulk redirect as there are alot of pages. Example:

www. mywebsite .co.uk slash products slash variables-that-changesw. h t m l

What I need to know is what I put in place of a variable, I have included a dollar sign but that does not seem to work can any one help me out here, thanks in advance.
Do you use google webmaster tools?

Site configuration > Change of address then follow the steps. This should hopefully help you in keeping those results.