//  Google app script column to array indexOf
var numRows = sheet.getLastRow();
var nameRng = sheet.getRange(2, 3, numRows).getValues(); // this is [[v1],[v2],...
var nameArr = String(nameRng).split(",");   // force column range into a String() and then split() it back into an array
if (nameArr.indexOf(inName) > 0 )