Even better, you can copy an attachment in a mail in Outlook, and paste it into an application running on another computer via RDP. The file will be copied over without the applications knowing any better.

We use this so users can attach invoices and other documents they've received through mail to orders in our application. Users typically run Outlook on their laptop/PC, but our application as a published application.

We rely on Excel exposing the data in an XML format on the clipboard to reliably import data from Excel. Same for Open/LibreOffice. Without it it's impossible to handle cells which contain both the quote character and newlines, due to the way Excel formats plaintext.

We don't want to import the whole file, because the users typically only need to import parts of the spreadsheet. This saves us from writing a complex UI to select the data to import.

And FWIW, I've used that with >100k rows of data.