Php a Excel

Solo necesitas grabar una Tabla HTML y salvarla con extension XLS. EXCEL reconocera automaticamente el formato.
Ejemplo:
Código PHP:
<?php
$shtml="<table>";
$shtml=$shtml."<tr>";
$shtml=$shtml."<td>Id</td><td>Codigo</td><td>US$</td>";
$shtml=$shtml."</tr>";
$shtml=$shtml."<tr>";
$shtml=$shtml."<td>1</td><td>C4325</td><td>2000.00</td>";
$shtml=$shtml."</tr>";
$shtml=$shtml."<tr>";
$shtml=$shtml."<td>2</td><td>DX456</td><td>1000.00</td>";
$shtml=$shtml."</tr>";
$shtml=$shtml."<tr>";
$shtml=$shtml."<td>3</td><td> </td><td>-50.00</td>";
$shtml=$shtml."</tr>";
$shtml=$shtml."<tr>";
$shtml=$shtml."<td>4</td><td>A18-TG</td><td>20.64</td>";
$shtml=$shtml."</tr>";
$shtml=$shtml."</table>";
$scarpeta=""; //carpeta donde guardar el archivo.
//debe tener permisos 775 por lo menos
$sfile=$scarpeta."/xxxx.xls"; //ruta del archivo a generar
$fp=fopen($sfile,"w");
fwrite($fp,$shtml);
fclose($fp);
echo "<a href='".$sfile."'>Haz click aqui</a>";
?>
Salu2