Within a Google Docs spreadsheet, I need to access external data that requires basic authentication.  Usually I would include external data by putting this in a cell:

    =ImportHtml("http://somedomain.com/somepath", "table", 0)

For basic auth, I have tried a standard URL with credentials:

    =ImportHtml("http://user:[email protected]/somepath", "table", 0)

Google responds with the following:

>error: Data temporarily unavailable

Is there any way to use basic auth-protected resources in a Google spreadsheet?