How can I move an event to another calendar?

We have 30+ calendar at our server and I have all on my client. If I set an new event to a calendar I select first at the left panel the calendar and then open a new event. The event will stored at the highlighted calendar

But if the event already exists, how can I change the calendar source?
At Thunderbird it was very simple - just open the event and select the account from the listbox - that’s it.
At emClient if I do this I get a message to invite my colleague but I cannot move the event so…

How can I do this?

Right now you have to drag the event on the calendar you want at into and it is move to that calendar.

I also prefer the changing the calendar in the event-details.
Requested here:

OK thanks that’s a possible solution - better than nothing.

I’ tried it by the listbox at the calendar details (scheduling tab) but it didn’t work. So I don’t know what this listbox means. Normally here I see the event source account.

If I change a the account here I get an invite dialog to invite the new user. If I cancel this dialog and reopen the event again the listbox entry just rolled back to the default account, which is a email account… this makes no sense.

You can change only organizer by that listbox.