integer numbers for new column calculation

Hi,

I have a small issue: my dataframe contains two columns - OrderedQuantity and DeliveredQuantity which contains decimal and integer values. I need to make a new column like this:

=0 in those rows where OrderedQuantity and DeliveredQuantity has integer values

= OrderedQuantity-DeliveredQuantity where OrderedQuantity and DeliveredQuantity has decimal values.

I was thinking about using ROUND() function:

= if [OrderedQuantity]<>ROUND(OrderedQuantity,0) and ... then [OrderedQuantity]-[DeliveredQuantity]

But it is not working. Can someone suggest other solution?

Thank you a lot