title: index and match to external file
body: <p>I am trying to create a function that preforms an index and match (vlookup) to another file.  I have a file that is zipcodes in ColA with a relative cost factors in ColB.  I often find myself copying and pasting that sheet into my workbooks and doing a vlookup.  is there a way that i can create a "Function" where the only argument is the zipcode and it returns the cost factor for that zipcode without having to copy and re-write an index match function every time.</p>
  
  <p>Thanks!</p>