This is very simple, I think, but not for me. :-)

I have 90 numbers (from 1 to 90), and when I press the button, one number is
shown in cell A1. I press button for the second time, second randomized
number (but number before is excluded from randomizing) is shown in cell B1,
etc. and when is 20th nubmer shown in cell T1, 21st nuber goes to second row
in A2, next in B2...
41st in A3... and when is 90th shown next display in cell A6 "Stop".

Thanx.