Joomla to WordPress

Great plugin, but I can’t wrap my head around the regex.

The old Joomla URLs I am trying to rewrite are like /blog/123-this-is-the-title and the new ones should be /blog/this-is-the-title – how do I get these numbers and the first hyphen out? They are all 3-digit with a hyphen after it.

Any help would be appreciated.
Thanks