Suppress zeroes will only suppress the row if there are no non-zero or non-null values in the entire row.
If you are using QV11, explore using dimension limits to suppress the rows (move column14 to column1).
If you are using QV10, you could use the approach you started with, but you will have to apply it to all columns:
Expression 1: If(Column(14) <> 0, original expression1 )
Expression 2: If(Column(14) <> 0, original expression2 )
Expression 14: If(original expression14 < 20, 0, original expression14)
Tedious I know, but that should work.