Ronald, there are several methods by which you can directly cut one part with another and which one you use depends on the context of the feature you're creating.
You can use the knit feature to duplicate the surface that's going to be the channel and then use Intersect or Cut With surface or Indent.
If the feature is in another part in an assembly, then you can go to that assembly, edit the part you want to cut and add a Cavity feature, selecting the part you wish to do the cut with.
If the lip feature is a standard toolbody, you can insert it into the part you want to cut, use move/copy bodies to position the toolbody and then use the Combine tool to remove the the toolbody from the cut part. Combine absorbs the toolbody, so you don't have to clean up after your operation like you do with indent or Cut with surface.
I suggest you read up on those commands in the online help and then have at it.
John, Thanks this is a big help.