Thanks very much for the advice. I succeeded in setting up for HDR, using the Fn button as the start point, choosing Aperture priority mode, selecting the number of exposures and the size of the exposure steps (I selected 1.0) And it worked fine (with Photomatic Essentials version) and I am delighted with the results and the prospects it opens up.
However, I have two more problems. The manual says that to turn off the bracketing option you simple have to set the number of exposures required to zero. But when I do that and press the shutter for single shots, the shutter remains in bracketing mode and fires off seven times. So I cannot find how to get it back to normal, pre-HDR mode.
The second problem is in changing the size of the exposure compensation for the seven shots. I had no trouble at the beginning in pressing on Fnc and rotating the front button to get the largest available on the D700 (1.0). But after that initial success, when I try to adjust it to a lower figure by pressing Fn and turning the front wheel to change it, nothing happens.
So at the moment I can only shoot bracketed! Doubtless I have set something wrongly somewhere. Any suggestions gratefully received. Incidentally, the camera has not been overworked: I bought it three years ago and the number of shutter releases is still only about 1600.