Dear Jeff,
First of all, thank you for your detailed explanation. Actually, you were right and it makes total sense. I did install NDxHD, but I guess it might have been a different version or something? I was able to export a .mov thanks to your explanation from AME. Now, still some details about your response:
1) I still cannot see the codec in the PRESET section after installing the codecs from your link. Check out the picture. I chose Quicktime in format and I still don't see the dnxhd, therefore I cannot choose the proper option there.
2) Nevertheless, I did what your graphic demonstrated. Nevertheless, I had to customize everything: frame rate, size; since I couldn't place the correct preset since dnxhd doesn't show. Is this normal? This vid for example was meant for slowmo, so I recorded 60fps. I had to modify the frame rate for this, and the width and height.
Thanks so much in advance for your answer!
Elaine