Obtendo a letra do drive de CD-ROM

function FindFirstCDROMDrive: Char;
var
drivemap, mask: DWORD;
i: Integer;
root: String;
begin
Result := #0;
root := 'A:\';
drivemap := GetLogicalDrives;
mask := 1;
for i:= 1 To 32 Do
begin
if (mask and drivemap) <> 0 Then
if GetDriveType( PChar(root) ) = DRIVE_CDROM Then
begin
Result := root[1];
Break;
end;
mask := mask shl 1;
Inc( root[1] );
End;
End;