Well,... wings is really set up to do solid models only, so this might seem a bit awkward, but here is what you can do.
1. create a "Grid" object. (This is a primitive available under the right click menu.)
2. move your points around and create new edges/verts to get what you want.
3. now select the bottom and side faces, right click and assign them the material "hole" They will now be colored blue in wings.
4. now export the model,... any faces with the hole material will not be exported and you will have just the plane you want.
note: if you then import the mesh back into wings, you will again have a non-legal mesh, since it is no longer a closed mesh.
Hope that helps.
1. create a "Grid" object. (This is a primitive available under the right click menu.)
2. move your points around and create new edges/verts to get what you want.
3. now select the bottom and side faces, right click and assign them the material "hole" They will now be colored blue in wings.
4. now export the model,... any faces with the hole material will not be exported and you will have just the plane you want.
note: if you then import the mesh back into wings, you will again have a non-legal mesh, since it is no longer a closed mesh.
Hope that helps.