Working with: Solidworks 2009, professional.

I'm designing a wireless transmitter for an audio microphone, and I've got two shell components, labeled pcb cover and outer housing.  For aesthetic appeal, we have a UI section on the pcb cover that is bell shaped, and a matching curve in the outer housing.  we've decided that for assembly purposes, we want to get a snap feature going all the way around the 3D curve of this bell shape.  I've modeled both parts separately and I've tried to perform the lip/groove feature, but for some reason, I can't get the feature to work properly.  There's little information available that I understand about the limitations of the feature, and I'm not sure if I am attempting something that the program cannot do or if I have not used the feature correctly.

In addition to this, I've included a test part, where I have attempted to use the split body feature using a surface body, hoping to have better control over the seam between these two parts.  Unfortunately, when I do split the bodies apart, they both take the form of cylinders, without the required bell-shaped cutout.

my question is this, is it possible with my current tool to have a lip and groove feature that follows a 3-dimensional curve, and if not, what would be the best way to carve a lip into these faces that the pcb cover and outer housing can be assembled?

Thank you, and best wishes.