I want to display a result as conditional formatting in a bar (could be a
cell) where you always see the full range of values (displayed in color
gradient, e.g. red to green) in a bar/cell and the result is marked with a
pointer (e.g. black arrow).

Example:
the value range goes from 1 to 3 whereas 1 is the best (= green) and 3 is
the worst (= red). Lets say I calculate a result of 1.8. This result in
displayed by an arrow which points to the appropriate position in the cell or
on the bar and therefore should point somewhere the color gradient shows
yellow. Additionally the maximum, minimum and current value should be
displayed as number.

Thanks for your help!