On your 80 MB file select the data range you want to import.
Click the name box (upper left part, next to the formula box).
Type a name for the data range.
Be sure to have column headers in Row 1 of your data range.

In a new workbook select e.g. A1
From the main menu select data--get external data--ne database query
That will display a dialogue box. Select "excel files" and click ok
That will display a file open dialogue. Select the Excel file you need
(the 80 MB file)
On the next screen click the name you gave your data range, then click
the right arrow "" to move the filed names into the right hand box.
Click next
On the next screen you can define selection criteria.
Click next
On the next screen you can define sort criteria
Click next
On the next screen select "view data in Query" and click finish
That will open MS Query
If you don't make any changes click "exit"
There are a few options on the next box which I would explain when you
want to go that route. For now click ok
Look t the results and let me know if it's what you can work with.

Hans