My site formally used a URL rewrite component called LinkFreeze to change the URL's to "SEO friendly URLs".
EX: 'www.mysite.com/category.asp?cat=3&subcat=2' would be changed to 'www.mysite.com/category~3~subcat~2.asp'
Moving forward to 2018... I'm unable to use this component anymore so there are thousands of orphan URL's out there. I wrote a simple script for a custom 404 page that redirects the URL to the correct (original) format of 'www.mysite.com/category.asp?cat=3&subcat=2'. This works, but I was hoping there was a way to do a 301 redirect using URL Rewrite. I'm open to any suggestions.