1: 2:
RewriteRule ^(/folder1/folder2/[^_/]+)_([^_/]+)\.htm$ http://www.newdomain.co.uk/folder1/folder2/$1-$2.htm [NC,R=301,L] RewriteRule ^(/folder1/folder2/[^_/]+)_([^_/]+)_([^_/]+)\.htm$ http://www.newdomain.co.uk/folder1/folder2/$1-$2-$3.htm