Showing the period values from data of exicuted report

Hi All

I am executing a BEX query in Analysis office excel & designing workbook. And further creating a automatic alerts & dashboard in one of tab in the same excel.

Issue:

I wanted to show the Period values or range of Periods as per the data displayed in the query and I kept BLANK for period in the input variable selection while executing the report. Hence when I display variable values with "SAPListOfVariables" the period values are not shown.

Requesting for your inputs to proceed further.