Edit BEx structure ouside BEx Designer

Dear Experts,

I have a strange Customer wish:

is there any option to edit/change BEx structure (global or local) used in the particular BEx query - without using BEx Designer??

An practical example:

I have a BEx query with several restricted rows (structure) and month in the column (just one KYF). This query is a basis for a graph (like several data series, each serie is a restricted selection in the structure).

User would like to have an option to add another selection / series, without changing the query in BEx Designer.

My idea is to create some ABAP function to make a change to the structure and regenerate the query.

Any idea how this could be possible?

Which tabled do I need?

Maybe FM with such function?

Would the change (new record in those tables be recognized as a structure change?

Thanks,

BR Tom