Replace character in Redirect Url

Hello,

In URL REwrite 2.0, is it possible to replace an underscore character with a hyphen inside a redirect variable?

For example, the {R:5} variable contains an underscore character. In the Redirect URL I would like to use {replaceUnderscore:{R:5}} similar to how you can lowercase R:5 like {toLower:{R:5}}

Any ideas?

Thanks!