You can create this part and flatten it out, however it will not give you the flat pattern it sounds like you're looking for. To do this, you need to make a punch, then deform the material. The reason I say you may not get the flat pattern you want, is that this will draw the material out, deforming it as opposed to just bending it in one direction (which is how Pro/E generates flat or formed patters).
I have done my share of complex formed sheet metal parts with single and even compound deformations (this gets tricky as you have to do all of the forming on a single punch). Through my many models, I have found it is best to make the part a sheet metal part as early on in the process as you can, and using only the sheet metal modeule if possible. This reduces the chances that you make features that cannot be flattened. My company requires every part have a flat pattern.
Going back to the punch however, I would suggest watching a video of how to do this as it is tricky to explain. It also still takes me a couple of tries to get it just right.
