WF 4 customized .hol files

I am looking to implement some standards into hole features using WF4, in this case blind holes. I would like to specify the thread length for blind holes and have a relation (or something) that adds a fixed value to determine the correct drill depth. I do not see how to do this by customizing the .hol files, but I am hoping there is a way.

IE for

1/4-20 UNC drill_depth=tap depth+.250

5/16-18UNC drill_depth=tap_depth+.278

etc.

This will then drive pro/manufacture later in the process.

Please advise what others are doing to make this work as robust as possible.

Thanks,

Bill Chapman

Sencon