{msg desc="Says hello and tells user to click a link."}
Hello {$userName}! Please click <a href="{$url}">here</a>.
{/msg}
what set config file or request params in plovr?
You can use this fork of plovr which has support for soy translations via XLF (doesn't come with default plovr). You'll need Java 7 to build/run it.
https://github.com/rgpower/plovr/tree/soy-translation
See the most recent commit for plovr cfg syntax related to XLF translations.