Google-sheets – Formula to populate one column based on the value in another one

Try this formula for cell H2:

=JOIN(", ", FILTER(B$1:E$1, B2:E2 = 0))

This filters the header row (B1:E1) on values from B2:E2 which has the value 0. The resulting strings are joined with ,.

You can copy this formula to the other cells in column H by dragging it across. The B2:E2 will adjust automatically to match the other rows.

Feel free to look at and copy the example spreadsheet I've set up.

You only use the exclamation point following the sheet name, not the cell -

=A1 + 'Other Sheet'!A$2

Use dollar signs for absolute references.