Get the 1-based index of an Excel cell given its column name

index.js

var baseCharCode = 'A'.charCodeAt(0) - 1 // Index is 1-based in Excel Interop

function excelColIndex(colName) {
  var index = 0
  for (var i = 0, pow = colName.length - 1; i < colName.length; i++, pow--) {
    index += Math.pow(26, pow) * (colName.charCodeAt(i) - baseCharCode)
  }
  return index
}