So, here it is:

1998-11-13  Miguel de Icaza  <miguel@nuclecu.unam.mx>

	* src/sheet-autofill.c (autofill_cell): Simplify by using
	cell_set_formula_tree

	* src/expr.c (expr_parse_string): Take a sheet argument
	(expr_decode_tree): Same

	* sheet.c (cellref_name): Now takes a sheet argument and decodes the
	cellref depending on the sheet.

	* cell.c (CellRef): Now they include the sheet location.