converting excel if function into a ssrs iif function

I have an excel spreadsheet that is using the if function to calculate the days and hours in a certain status. For example, If the columnSpecimen Delivered  is populated, then the columnTime after Specimen Deliveryshould calculate the days and hours it has been in that status from current datetime. I am trying to duplicate this in ssrs report. See screen shot below. Can someone help please? Thank you in advance.