a report with several field

Element
Value
Min
Max

The data comes from a table where there is always a 0 in the fields min / max
I would like to put some kind of expression in the field min and max on the report that if the field value is Null (or empty) it will show the value from the field min or max or alternatively that the field min or max will only be visible if the value is > 0

Can someone help me out with this?