title: How do I make Excel user-defined function (UDF) accept arguments of String type and range type?
body: <p>I am trying to make a function <code>do_something_to_string(one_arg)</code> where one_arg can be of string type or be a range.</p>
  
  <p>In the case of a range, I want to concatenate every cell of the range into one long string but processing. But I can't seem to make a function that can accept either a string or a Range as argument.</p>