Max Depth is possible?

Could someone help me how to set a cut-off for the Z axis such as a MAX DEPTH where the machine would continue to cut but not exceed the limit marked?

Thanks John,

I'll try to explain better, maybe a suggestion to developers.

Working with a multicam 3000 series, and it have a configuration tool where you can set the MAX DEPTH, that she knows where my desk and just will not go that deep even though I set the cut for this, so when I set the zero axis Z, I go in and define MAX DEPTH my cutting tool can still pass 0.25 mm further to ensure that the cutting is completed properly, so the table of sacrifice just about having a longer life. Example: I program a cut of a circle, the material to be cut is 3mm, after checking the home work and set the zero of the Z axis I still define the max depth is 0.25 mm below zero in programming I can put up to 4 mm material that he will not spend more than the 0.25 mm from the zero set Z axis

I have said it better.

Thanks again!