I have some trouble with special characters in the product URL:s. Mainly use Swedish products and the letters å ä ö are common. Read the similar post here https://www.pricetapestry.org/node/542 and tried your provided solution - without luck unfortunately. With the provided fix i get a rewrite from å ä ö to ? in the URL. What i want is the following.
å > a
ä > a
ö > o
Any ideas how to modify the solution to fit my needs?