[libvirt] F10: how to save snapshot back to image?

In Fedora 10 I've managed to get libvirt to call the emulator with custom arguments so I can invoke -snapshot. I just replaced the emulator in /usr/bin with my own script which adds the argument and then calls the original emulator. This works fine. And the snapshot works fine. I can make lots of changes and when I shutdown and restart then all the changes are forgotten. Now after I'm satisfied with some changes I want to save the snapshot back to the image file. I've tried "Ctrl-Alt-s", but this does not work. I tried finding the QEMU console, but Serial Console is grayed out in the menu. I don't know if that would help anyway since this was a raw image and not qcow2 so I don't think 'savevm' and 'loadvm' would work with raw. Can someone tell me how to save these snapshots back to the image file? Thanks. Regards, Gerry