If you assign the cell a range name you can refer to the cell by its name and
it won't matter what the worksheet name is.
Move the cell you want to reference and click INSERT on the menu, select
NAME from the drop-down menu and then DEFINE from the cascade menu. The
range name must start with a letter, it cannot have any spaces and the only
acceptable characters are the letters a to z, A to Z, or numbers or the
underscore.
By default range names are absolute references.
To use a named range in formula you can use the range name instead of the
cells addresses:
=SUM(MyNamedRange)
=A1*MyNamedRange
and so on...