Fixed iso and aperture

I'm trying to set up a user mode on my K3 that will give a five shot bracketed exposure with a fixed iso and fixed aperture. But I can't figure out how to do it or if it's possible.
Any ideas?

On a K5II just use Av- Aperture priority, this just changes the shutter speed to adjust the exposures. Probably the same or similar on other bodies. These days I do exposure bracketing manually, gives you total flexibility and control.

Unfortunately, Nigelk, that doesn't work. although the aperture is fixed, the shutter speed and/or the iso is altered. I want to have fixed iso and aperture. Also I want to do it hand held for HDR. It may not be possible.

Does Nigel's suggestion not work if you take the ISO off the Auto setting?

???
At least 1 of the 3 values has to change otherwise it's just the same shot.
I think you can set the range of iso, to a minimum, but something has to change,
Or am I just not understanding your point ?

Yes, I just want the shutter speed to change. I'll try limiting the iso range - never thought of that! Sometimes the obvious doesn't leap out!
Thanks

Five bracketed photos with fixed iso and aperture only leaves the shutter speed to vary the exposure.

If you have a fixed iso then this should work fine. I found changing the iso settings a bit difficult at first, but you definitely should be able to achieve what you are after.

that's the answer. Av and limit the iso range.
thanks everyone

Glad you got sorted