You can try using Obj-Filter method to filter the results based on the condition. Also, you can try calling an inner loop and pass the index of the current loop page to a property as parameter. This will delete the page from the pagelist. It can also be done on a condition.
You can use "for each page in" method in Datatransform and give ExceptionList.pxResults in the target and use a when condition to check if FacilitySubType="Express" and then use Remove method to remove the page if the condition is satisfied