Output file name - Scheduler

Hi all,

I have found on the forum that when using the scheduler, the output file name can get a date using one of following tags:
%YEAR%
%MONTH%
%DAY%
%HOUR%
%MINUTE%

We have a customer who want to plan a report which gives him info about last month. When scheduling this report, it would be nice that the previous month number would be in the output file name. Is there a possibility to "calculate" it? Something like: "%YEAR% %MONTH%-1 Info about last month.xlsx"?

Thanks!