on a saved search in a sublist, is there a way to add an "export to excel" or csv button?

Copy the "download to excel link" from the search when you have filtered it. The URL should contain filter-parameters. Create a button on the form with that link. You can create the button either with a inline html field or a beforeload-script.

I added a button yesterday to export a table to csv w/ a button and a client script. it's a bit hacky as it grabs the table element to convert to csv, but functional and fast. https://stackoverflow.com/questions/15547198/export-html-table-to-csv