If you actually want to place shadows at certain tones, I would start by rating it at 800 or 1000, and learn to develop to get the highlights where you want them. It's a beautiful, low contrast film with a nice, neat grain pattern. You may want a neat grain pattern for some things, and you may want a more clumpy, random type of grain for other things. This is definitely more of the neat grain wash look than the grungy clumpy grainy look. It can be stunning, or very ugly depending on how much testing you put into it. It has a very neat look in medium format. It's also a great way to get grain without getting excessive contrast.
However, most don't use this film in the most controlled situations, and/or situations where shadow detail is all that important. Therefore, it is most often rerated on folks' light meters as opposed to being used with a personally established EI and tightly controlled for contrast with film testing and the like. In these cases, you should realize that whatever EIs you use that are above 1000 will really be based only on how far you can push the highlights, and not on an actual "shadow film speed". Your shadows start going down the tubes when you rate it over 1000. Not a bad thing, but something to be aware of. Delta 3200 is not unique in this, though. It's the same with uprating any film with the intent of pushing it in development. Delta holds the shadows better than most films, though. It's great because it is so low contrast to begin with, therefore holds both shadows and highlights very well, so it can be pushed quite far before it becomes hard to print.
Check development charts for starting times when rated at various speeds. Ilford charts tend to be very close to the way I process film. That is not always the case, though, so you should do your own tests.
I love this film. It has so many uses, some of which are obvious, and others which are not so.
Also of note is that the term "ISO" is not connected to the "3200" in the film's name. That's because Ilford says it is ISO 1000 if you read the data sheet. "Delta 3200" is simply a product name, not a statement of true film speed. I would prefer if they simply called it "Ilford Super Speed Delta" or something like that.
As far as your actual question:
If you want to use it at 3200, you can. All you are doing when you set your light meter's ASA is telling it how much to amplify whatever level of light it is reading. You are not actually changing anything about the film (obviously). So, it is really just a shortcut to underexposing the film, which you can do manually anyhow. If you can get it to 1600, and your camera also has a -1 setting, you are in business. If not, simply give half as much exposure as your meter indicates. This means one smaller aperture or one faster shutter speed. This will give the same exposure as rating it at 3200. Then develop for 3200, or course.
2F/2F