So I repeated the experiment with 5 second exposures from a fixed tripod with my Canon Digital Ixus 400 compact camera at maximum zoom. The result is much better than the previous attempt a few days ago. This image, a stack of 16 photographs exposed 5 seconds each, highly satisfies me!
I also took a number of 10 second wide field images again. Below image shows (a part of) a stack of 8 wide field images, 10 second exposure each. The full constellation of Perseus is visible, with the comet as a bright yellowish object just above the alpha Persei association.