Copying from one workbook to another

[mevetts]

Hi

Is there a way of automatically copying cell data between workbooks without having to open both workbooks.

I am recording student attendance - each class has a dedicated workbook where absence is entered and a total created.

I would like to copy this total into a separate workbook automatically, without having to open the individual class workbooks.

I have tried =[L6 Ec B1.xlsm]Sheet2'!$B$7

But when I reopen the workbook it says it can't locate the data.

I have 15 separate registers that I want to feed into one master spreadsheet.

I am using Excel:mac 2011

Thanks for your help.