When using the indirect( ) function that points to cells referring to
external workbooks I get a #REF error when the external spreadsheets are
closed.

e.g. Cell A1 of workbook "testing.xls" has the following text string in it:
'test1.xls'!sheet1$A$1 , in cell A2 of "testing.xls" I have the following:
=INDIRECT(A1), the value returned is 4000 (the same as the value in A1 of
workbook test1.xls.) The problem is tha the value is only returned when
test1.xls is open, otherwise #REF is returned

Please help.