Redirect url by alternative alias field

Hi,
I need to redirect url for example site.com/siteid=1
to site.com/somepage1
???

I know I can do it with .htaccess, but I have a lot of products which will be linked from some other webpage by productId=xxx and address od my product on my page is:
site.com/product-with-some-name

So my idea is to have an TV where I would add alternative id number productId=xxx and this will redirect to correct page..
Is there any way how to implement this?
Thanks