Can I perform tasks on a closed Workbook
 

I was wondering if I had to open up a workbook in order to extract data,
filter, sort, delete rows etc.?

I already use the workbook().Worksheets() notation to deal with open
workbooks.

Can I perform tasks on a closed Workbook
 

Well I dont believe there is any way you can do data manipulation while
the workbook is closed...but you could have your macro do the opening
of the file...so you dont have to open up the workbook...would that
help?