TI really needs to put in a MEMBER function, because the FOR method can take a long time if the list is big. I'm not sure if the 83 has INSTRING (89 does : ), but if it does, you could always parse everything into a string (separated by commas or spaces) instead of a list and use instring to find the coordinate of the first appearance of what you're looking for. (But that can get really confusing.)