Google-sheets – How to create draggable sheet reference with the same cell

From inside the Google spreadsheet, go to Tools -> Script editor then try this:

function onEdit() {
 var s = SpreadsheetApp.getActiveSheet();
 if( s.getName() == "Sheet1" ) { //checks that we're on the correct sheet
   var r = s.getActiveCell();
   if( r.getColumn() == 1) { //checks the column
     var ss = SpreadsheetApp.getActiveSpreadsheet();
     var XSheet = ss.getSheetByName("Sheet2");
     ss.setActiveSheet(XSheet);
     SpreadsheetApp.getActiveSheet().getRange(r.getRow(), r.getColumn()).setValue("X");
     var MainSheet = ss.getSheetByName("Sheet1");
     ss.setActiveSheet(MainSheet);   };
 };
}

This assumes your sheets are named Sheet1 and Sheet2, as is the default, and it's set to only watch column E (5) on Sheet1 for edits and only add an "X" to the corresponding cell in Sheet2.

I found the answer:

=INDIRECT(A9&"!B2")

A9 = Cell, which contains the name of the sheet you need to referrence B2 = Cell with data in sheet you need to referrence