Replace any number of spaces with comma

That's wonderful Mr. Karedog
It works like charm

I am greedy as you know .. How to add another point
Example :

"-, Hello - , -     , This , , , - , Test Only, Thanks a lot"

The needed output would be (Remove any commas and dashes and the spaces more than two with comma (as done)
The desired output would be

"Hello, This, Test Only, Thanks a lot"