I guess not. I tried linking to an excel file, exported an interactive PDF, tried my button – boom: Excel lauches. I was kind of confident the export-option to "form and media: embedd" will embed the excel file. But as I renamed the file on my hdd, the link was broken.
Only option I see is to save the excelfile onto a google-drive or a hosting cloudservice. But Im afraid you need your PDF to be stand-alone, not requiring the internet…
Another thing: You can add PDFs into excel. If you assume the people to have Excel, why not the other way round?
One workaround which may work for you is to deploy your PDF and its relevant associated files in a single folder, rather than as an attachment to the PDF.
When I was doing self-paced training courses, I'd pack PDF lessons in separate folders, then link them to associated files in the same folder. That's not the same as an attached file to a PDF, of course. But by placing the PDF and the linked file(s) in the same folder, then establishing the links, the file references would be relative links within the folder rather than absolute links to a file loaction on a system, network or cloud drive. Then I could simply copy the entire folder onto a removable drive and maintain the relative link.
You may want to experiment with this, and offer a zipped file folder rather than a PDF with an attachment. If you do this, you probably want to include a readme file explaining how important it is to keep everything inside the same expanded folder for things to work correctly.