Sounds like a "no way". EZE is a detour, and there are some mileage issues - but the bigger problem is the injected foreign segment EZE-BOG. If there is some FRA-EZE-AZE, chances might be better.

Go ask, and you may be lucky.
Yet, under normal circumstances, this is only possible with actual INVOL - defined as "short-term" in first place, IIRC not more than one day before first flight affected.

If you are sort-of flexible wrt flight date: Try to find a date where there is a higher booking class on a similar routing (Saturdays tend to be more busy, for example).
On CNX there should not be that much restrictions regarding dates and classes. It would be much better, if it was a LH segment that got canceled. Your case is called CNXOAL (canceled by other airline), see page 7 for the difference: Look here
The text is for travel agents actually. But for my understanding, it describes the general rules (from LH's pov).

My personal experience is that the agents on the phone are quite liberal at the moment, as long as your ideas are not overly "maximized". And always remember to be "sweet and nice"