how to redirect .htm to .aspx

I am trying to redirect all .htm pages to .aspx pages.

This code works, but how can I make it work for any file name?

<location path="features.htm"><system.webServer><httpRedirect enabled="true" destination="/features.aspx" exactDestination="true" childOnly="true" httpResponseStatus="Permanent" /></system.webServer></location>

Thanks

Vaclav