Linking To different workbooks using formula's

Hi All,

I am new to the site but have used it a lot(if you know what i mean).
I have a summary workbook that links to various other data workbooks and i am sick of writing the formula's to link them to the cells in the other data workbooks.

I would like to know if there is anyway of using a formula to link them.
The data workbooks are numbered by week Eg "Week 1" so i have been trying to use indirect.ext and a concatenate but have had no luck so far.

My formula currently is
=indirect.ext(s:\line 1\line 2\line 3\("["&B1&".xls]"&"Sheet1'!$A$1")
In cell B1 is "week 1" without the "marks.

Hopefully someone is able to help me as this is driving me insane.

BTW i have downloaded the add in of morefunc so that the function of .ext works.

Thanks in advance