The number needs to have a length of 12 and 2 decimal places.
Probably there's a solution with "=RAND()".
Lots of answers, but here is my solution:
=RANDBETWEEN(1000000000,9999999999)+RANDBETWEEN(1,99)/100
This formula will produce a random number and also a random decimal place, decimal numbers produce by dividing the decimal place numbers by 100 and adding them to the whole number.
Make sure you format your cells as number with 2 decimal places.