Kevin,
Just select all the lines you want,then create a tool, you then just apply the cut depth to all the lines and post code.
Note that if you do not set the cut depth then LC will default to some values including feedrate and Z retract which you may not want to use.
All in the manual, take a look at Tutorial #1, don't hack you way through LC. The manual can be found in Memebers Doc's.
RICH