for what it's worth, 'daremo' is usually considered a word meaning 'anyone'; such as in 'daremo inai' - 'there isn't anyone there'.
But though it gets its own dictionary entry, 'daremo' is just a compound of 'dare' + 'mo'.
'donata' is just a more formal version of 'dare' and so even if 'donatamo' doesn't rate a dictionary entry of its own, it's still the same meaning.