Sinister, CAM laid out exactly how to do this. If you want to have a variable length bar, w/ a hole 1/2" from either end and a set # of holes, then his, is the proper way to accomplish it.
If you are using bars which have a length that corresponds to the c-c dim of your holes, then you are correct. Put in a pattern w/ 1000 holes and the ones which don't 'hit' anything won't show up.
If you want to have a variable length bar with a pattern of hole which always start and end 1/2" from either end of the bar, and the hole pattern c-c is not set in stone but must fit into some min/max numbers then this can be accomplished w/ DriveWorks Express [if you have '08]
One way or the other, what you need done.. can be accomplished..
JerryFlyGuy
The more I know... the more I realize I don't
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)