Select the cells you want in the range (A1:AB20)
Click in the Name Box (on the toolbar, below the font type: should show the current cell at present, eg A1)
Type your range name, eg MyRange, into the Name Box and press enter.
Maybe this is what you are seeking?
1. Select cell AC21
2. Press Cntrl+Shift while tapping sequentiallyright arrow, then up arrow, then down arrow)... then finally release the Cntrl+Shift keys.
3. Click Format/Column/Hide.
4. Click Format/Row/Hide.
5. What's left is just the cells you are concerned with: A1:AB20. Everything else is just plain gray.
Cheers! /s/ Larry