Accessing the XML API from Excel - authentication issue

I am trying to access the XML API from Excel. If I embed my User Token in the request URL, things work fine: I go to Data -> From Web, paste in my query URL, and after a little drilling down, I got my data.

HOWEVER: The spreadsheet that calls the API is to be passed around, and word on the street is that leaving my User Token in a shared document is Not A Great Idea(tm).

If I use the query URL without my User Token, I get an authentication window of sorts from Excel, but if I select the Basic tab and enter my credentials, I get a message "We couldn't authenticate with the credentials provided. Please try again".

My goal is to have every user enter their own QuickBase credentials when refreshing the data in the spreadsheet. I can't use the QuickBase add-on for Excel, and I can't create a shared account to access the data.

Is there a good way to do this?

Thanks!