 <p>If using FieldSetText, you have to be careful to format the value in a way that's consistent with the user's preferences and/or the settings of the field (e.g. whether the decimal separator is "," or "."). To avoid this source of error, it's better to use the NotesDocument object for this sort of thing. You need a better reason than "I don't want to," to not do this.</p> <p>You could use the NotesDocument for this one operation and the NotesUIDocument for everything else, e.g. write:</p> <p>uidoc.Document.ReplaceItemValue "fieldname", numbervalue</p> <p>Unless you've deliberately set the option to not reload the UI automatically, this will do what you want. If you have set that option you'll need a second call to do that update.</p>