Random select time from game clock

[catiexcel]

For quality analysis I want to select a random 20 minutes from a 80-minute rugby game. How do I customise the '=TEXT(RAND(), "MM:SS")' so that its giving me a starting number between 0.00 and 80.00?

 

[JamesCanale]

I stole Fluffs formula of course, then made a separate 10 more random times, then filtered those for times that were more than 10 minutes apart, then took the first of that filtered group. A vstack would serve better at the end, but I don't have that yet.