[solved] Insert value from cell into formula

I’m puzzling with the following question.

I’m pointing to the cell Setup.$C3. However, the 3 should be a value from another cell (in row E (same sheet, not setup), like 3,4,5,6 et cetera). Just tried several options like:

setup.c&(E3)

setup.c&"E3"

et cetera.

How can i use a value from row E into a formule and combine it?

You’ll want to use the INDIRECT function that converts a string to a formula, that is:

=INDIRECT("Setup.$C"&E3)

Thanks! Never heard of INDIRECT until now.

This works fine.
But if you change the sheet name or insert/delete a column in A or B or both, the formula is not adjusted.

There are other options to do the job (see details and samples in the LibreOffice help):

INDEX returns a sub range, specified by row and column number, or an optional range index. Depending on context, INDEX returns a reference or content.
Syntax
INDEX(Reference; Row; Column; Range)

OFFSET returns the value of a cell offset by a certain number of rows and columns from a given reference point.
Syntax
OFFSET(Reference; Rows; Columns; Height; Width)