Hi can you please help me with a marco

I want a marco to generate random numbers between 1 - 100 in a single cell

for eg:
in the excel sheet I need a start buton and an stop button

if I click "Start" button, the Cell "A1" should start generating random numbers with half a second interval and if I click "stop" the number generation should stop

can any please help me with this macro

thanks a lot