How to pass the result of a select to another form for a $ _POST

I have two files

ExportDatos.php I have a form, where I enter the name of the executive and the date range

<div class="col-md-6">
     <div class="box box-primary">
        <div class="box-header">
          <h3 class="box-title">Ingrese los Datos:</h3>
        </div>
        <div class="box-body">
          <!-- Date -->
            <div class="form-group">
            <label>Ejecutivo:</label>




            <select id ="ejecutivo" name ="ejecutivo" class="form-control select2" type = "text" style="width: 100%;">
              <option value ="0">Seleccione:</option>
              <?php 
              $queryEje = "select nom_ejecutivo as nombre, apaterno_ejecutivo as apellido from ejecutivos_afa where estado = '1' and id_tipo = '2';";
              $resultadoEje = mysqli_query($cn, $queryEje);

              while ($valores = mysqli_fetch_array($resultadoEje)){
                  $eje = $valores['nombre'] .' '. $valores['apellido'];
                  $id_eje = $valores ['id'];
                  echo '<option value = "'.$id_eje.'"> '.$eje.' </option>';
              }
              ?>

            </select>
          </div>
          <!-- /.form group -->

          <!-- Date range -->
          <div class="form-group">
                <label>Fecha Inicio:</label>
                  <div class="input-group date">
                     <div class="input-group-addon">
                        <i class="fa fa-calendar"></i>
                    </div>
                      <input id="datepicker" name="datepicker" type="text" class="form-control" value="">
                </div>
                    <div id="errorDatepicker"></div>
                            <!-- /.input group -->
            </div> 
              <div class="form-group">
                <label>Fecha Fin:</label>
                  <div class="input-group date">
                     <div class="input-group-addon">
                        <i class="fa fa-calendar"></i>
                    </div>
                      <input id="datepicker1" name="datepicker1" type="text" class="form-control" value="">
                </div>
                    <div id="errorDatepicker"></div>
                            <!-- /.input group -->
                </div>
    <div align="right">
          <div class="btn-group">
            <input type="submit" name="enviarexportar" id="enviarexportar" value="Exportar" class="btn btn-info" onmouseover="validarExportar();"/>&nbsp;&nbsp;&nbsp;&nbsp; 
            <input type="reset" name="cancelarsolicitud" id="cancelarsolicitud" class="btn btn-default" value="Cancelar" />&nbsp;&nbsp; 
         </div>
        </div>
        </div>
        <!-- /.box-body -->
      </div>
    </div>

I have another ExportExcel file, where I receive by the method $ _POST the options entered

<?php
date_default_timezone_set('America/Santiago');
session_start();
include('../../../conexion/index.php');
require ("PHPExcel.php");

//Cabeceras de la Libreria de PHPExcel
header('Content-type: application/vnd.ms-excel;charset=iso-8859-15');
header('Content-Disposition: attachment; filename=Informacion_Ejecutivo.xls');



$id_eje = $_POST["ejecutivo"]; // Esta variable me llega vacio, por tal motivo no me ejecuta la sentencia SQL
$fecha_ini = $_POST["datepicker"];
$fecha_fin = $_POST["datepicker1"];