Data validation and external file

[weirdcpu]

Hello,

In Calc you can use a data validation list and use the data of another sheet

for example in a workbook named "roadmap" with two sheets :

- todo_list and workers_list

in a column of todo_list i can use a drop list, build with data validation, which use data from worker_list.

I can't find the correct syntax for declaring a data validation from a sheet in ANOTHER workbook.

Any help or example please