Pixnub
Yes, you need to make a new preset and turn on resampling. Then you will need to do a little math to enter the values. So if you want 4xx0500 pixels then yo can make it 4×5 inches at 100 PPI (or 8×10 inches at 50 PPI).
This is just an example of coarse so make the numbers whatever you want.
See this screenshot.
