One way to do it would be to use a floating field, and bind the floating field to text that contains either "I" or "We" based on what comes from the database.
You can create floating fields by right-clicking inside a Text object while you're editing it - it's on the context menu.
You can only insert a floating field while you're editing a text object - drop a text node, double-click on it to go into edit mode, and the option to insert a floating field should be enabled.
