Data Combining - Create 1 Excel Sheet From Many Sheets

I have an xlsx file that has about 80 workbooks inside it. Each workbook represents a category and has only one column in it with a unique ID in it. I need a single workbook created with a column for the identifier and then 80 more columns with a 1 or 0 in it if that identifier appears under a given category. So this is how the process would work for 1 category: 1) Open Master File which will already have about 300,000 rows in it 2) Copy all rows from category 1 into bottom of master file 3) Use CountIf function or other to identify records that appear under this category 4) Repeat for all categories. The files used in the example would be 2: 1) Master File With This Layout: Attorney Cat1 Cat2 Cat3.....80 --------- ----- ---- ---- AttID1 1 0 0 AttID2 0 1 1 AttID3 1 1 1 2) Cat1 File Attorney ---------- AttID1 AttID3 After all processing is complete I need any duplicate rows to be removed.