Stuck between a rock and a spreadsheet.

My responsibilities were expanded with the addition of a new to me team which has created a series of new stressors and nightmares for me as the manager. My original team worked in sales and marketing. My new team is completely unrelated and works in inventory control systems. There is no overlap. They are opposite ends of the customer lifecycle as the second team handles returns after contracts end and the original team creates the contracts. Here are my main issues.

1) The director is a little too invested in the minutia of this team.

2) It was an expansion of duties not the promotion.

3) Their software hasn't been updated in 25 years. Seriously. We're using an inventory management system from 2000 which makes it incompatible with everything except Excel and Wordpad.

4) Everything is spreadsheet based with this team. 25-75 MB files that go back a decade for no reason.

5) The system emails me 20-25 spreadsheets a day that have to be integrated into sheet for comparison and error checking.

There has to be a better way. I have to download six different reports from Salesforce, compare those to the inventory management spreadsheets that are emailed to me and I then compile into one spreadsheet by hand. I have no time for my other team. If I can figure out a better way I know I can get the director to back off. There's no buying a new system because I work for a pennywise and pound foolish multinational conglomerate. I've already handed off some of the spreadsheets to one of the seniors but the team is overloaded and hourly. If they aren't dealing with tickets, our numbers go down and the director grows more interested along with the VP. I got handed a sh!t show.

Other than applying to work elsewhere, any idea on solutions to handle my nightmare?