Some one trained in SOLIDWORKS SURFACES, Please

Within the last month or so I made a model for a hand held "Tenderizer" made of a rectangle, approximately 100 MM long and 38 MM wide, with a convex shape at the top.(raised radius). I offset a plane, and I sketched and projected a line on the radius and using the line as a path, I swept cut a 3 MM groove the entire width of the rectangle, then I linear patterned the entire curved surface. So now the surface is a row of grooves, cut along a raised radius, with a sharp raised line sticking up between each groove. The client now wants another model identical, except that he wants another set of grooves, criss-crossing the existing ones. I was able to project a line 90 degrees to the exisiting grooves, in hopes of being able to create a plane to make a sketch to sweep cut in the other direction, but Solidworks flat out refused to do it. Am I asking too much to be able to do this? If this is possible, I would appreciate anyone passing the technique on to me. If anyone needs to see the model, it is not a proprietary problem. Mike