query google sheet using column name

query-using-header.gs

function columnToLetter(column)
{
var temp, letter = ”;
while (column > 0)
{
temp = (column – 1) % 26;
letter = String.fromCharCode(temp + 65) + letter;
column = (column – temp – 1) / 26;
}
return letter;
}

function columnOf(columnName, sheetName, headerRow){
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheetByName(sheetName);
headerRow = (headerRow?headerRow:1);

var headerAddress = “A” + headerRow + “:” + columnToLetter(sheet.getLastColumn()) + headerRow;
var range = sheet.getRange(headerAddress);
var values = range.getValues();

for( var column = 0; column <= values[0].length; column++ ) {
if( values[0][column] == columnName ) return columnToLetter(column+1);
}

throw ("ERROR: NOT FOUND!");
}

//SO I USE LIKE THESE:
//=QUERY(data!A:C;CONCATENATE("SELECT ";columnOf("Year";"data")))