str_replace a .TPL variable?

[memorex]

I have a variable named {$user.login} that I use in a URL like this:http://profiles.mysite.com/{$user.login}I want to replace spaces with + symbols like this:"User name" becomes "User+name".This way, my links will be cleaner.Instead of http://profiles.mysite.com/User name I would have http://profiles.mysite.com/User+nameAny way I can do this? Thanks!