I have a workbook that contains several tabs named by years (eg Y2001,
Y2002, Y2003...).

Is there a syntax that would reference a cell whose worksheet is based
on the result of a formula? So, for example, if the formula resulted
in 2002, it would return the A1 value in the Y2002 worksheet instead
of any of the others

Something like this perhaps?

="Y"&formula_that_gives_a_year_value!A1