How to read refcursor column's using string column name?

[inspector morse <inspectormorse86@xxxxxxxxx>]

How do I access a cursor's column using a string column?

Example:

CREATE FUNCTION write_html_select(items cursor, data_value_field text, data_text_field text)

AS

$$

DECLARE r RECORD;

                html TEXT;

BEGIN

    FOR r in items LOOP

       html = "<option value=" || r[data_value_field] || "/>";

   END LOOP;

  RETURN html;

END;
$$

LANGUAGE plpgsql;

As you can see, I want to access RECORD r's columns by a STRING column name value (data_value_field etc)....is there anyway to do this?