When you use the filter functionality you can decide for only some rows (items) to be exported. More info here: https://help.podio.com/hc/en-us/articles/201019668-Exporting-to-Excel
However it is currently not an option to decide what fields/columns to export, all fields will be exported from the items you have selected.
Here's how you create filter and reports to filter on a date field:
Sara - Podio