Convert XLS to PMD

As far as we know, the only way to produce .pmd spreadsheets from MS Excel sources (.xls, .xlsx) is to use PlanMaker. It appears the PMD format used in PlanMaker is not that well supported in other spreadsheet programs, perhaps with the exception of programs based on Ashmapoo software. Nonetheless several more file types use pmd extension, so it might be very well possible that some other type of xlsx to pmd conversion exists.