So after some more sweating, I worked it out.
Here's how I did it.
In my controller:
$letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
for($l = 0; $l < strlen($letters); $l++) {
$adminExtensions[$letters[$l]] = $this->AdminExtension->find('all',
array(
'conditions' => array(
'AND' => array(
'AdminExtension.location_id'=>'3',
'HrEmployee.name LIKE '=>$letters[$l].'%'
)
)
)
);
}
$this->set(compact('adminExtensions'));
And in my view I did this:
$letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$k = 1;
for($l = 0; $l < strlen($letters); $l++) {
$this->PhpExcel->write('B'.($l+$k+1),$letters[$l]);
foreach ($adminExtensions[$letters[$l]] as $adminExtension) {
$k++;
$this->PhpExcel->write('A'.($l+$k+1),$adminExtension['HrEmployee']['name'] . ' ' . $adminExtension['HrEmployee']['surname']);
$this->PhpExcel->write('B'.($l+$k+1),$adminExtension['AdminExtension']['ext']);
}
}
It works perfectly! :)