Bodo, if I understand it correctly, for DXCC purposes, you may have another person go to your home station and work you.... The contact might not even have to be from your station, it might just be that you authorize them to use your call. I cannot find the actual rule right now, but I think I have seen it.
I doubt it counts for DXCC to work yourself from your own remote station, because it is sort of a conflict of interest to be both the person trying for the contact and the person giving out the contact

I'd probably contact the DXCC desk to be certain. I think some of the remote-base rules are in flux, or are not clear because this issue is somewhat new.
I do think there is a way for you to get credit for your activations that count for your DXCC from Germany , but my guess is that you cannot work yourself.