How to reference a cell from a document referenced by name from a cell?

Example: Calculated formula needs to be: =‘file:///C:/folder/spreadsheet_24-08-24.ods’#$Sheet1.E1
Result on A1 should be = 100

A1, what goes here?
B2 = spreadsheet_24-08-24.ods
E1 on spreadsheet_24-08-24.ods = 100

I’ve googled a lot and tried many things like A1 = ‘file:///C:/folder/B2’#$Sheet1.E1 which does not work, anyone know a solution?

This is on windows, Librecalc, Libreoffice version 24.8.0, Format .ods

Correct syntax:

='file:///C:/Folder/spreadsheet_24-08-24.ods'#$Sheet1.E1

Сheck the Apostrophe signs.
Also check the option setting:
Menu / Tools / Options / LibreOffice Calc / Formula. Formula syntax : Calc A1.

You can build the reference as text and then use the INDIRECT function on it.
=INDIRECT(CONCATENATE("'file:///C:/folder/";B2;"'#$Sheet1.E1"))
Instead of CONCATENATE you can use TEXTJOIN with an empty delimiter as well.
=INDIRECT(TEXTJOIN("";1;"'file:///C:/folder/";B2;"'#$Sheet1.E1"))