I need a formula please to display a result as follows:

If time sum of cell L61-98:00 resulted in a time more than 20:00 hours.
The formula should display please the extra time in hours and minutes over the 20:00 hours multiply by 1.5 plus the original 20:00 hours.
If cell L61 contains 98:00 hours or less, to display the hours and minutes over 78:00 only.

Example:
If Cell L61 has a time of 102:00
The end result formula should display 26:00

If Cell L61 has a time of 95:00
The result should be 17:00