virtual directories and URL encoding

For SEO reasons, they want me to rename the folder structure of our
site. I'm trying to use virtual directories for this. Problem is, I
have a virtual directory called 'baseball-shoes' (the '-' is there for
SEO reasons, Google sees that as 2 keywords, etc). When I try
mysite.com/baseball-shoes, the page comes but the URL shows as
mysite.com/baseball%2Dshoes. If instead I try mysite.com/baseball-
shoes/, it shows fine. How can I make it so it doesn't encode the
'-' ?