Variable Resolution Issue in XLS Export Filename

In a Table Portlet, I have defined he portlet title using variables as follows: “List from {startMonth} to {endMonth}”

In the web browser, the variables are resolved correctly and display the expected values (e.g., “List from March to May”).

However, when I export to xls, the resulting filename contains the literal variable names (e.g., List_from_{startMonth}to{endMonth}.xls) instead of their actual values.
As a user, i want to see in the excel the reporting period, either in the filename or within the document itself.
Is there a way to ensure variables are correctly parsed in the exported filename?
If not, is it possible to automatically insert a title header with these variables inside the Excel sheet, above the data table, during the export process?