ITV2 is on Sky channel 118.

It is on Sky channel 118 no matter what country you are in.

The only issue is where in Spain are you located and what size satellite dish you have installed.

In many areas of Spain, along the Mediterranean coast, you may well need a 2.4m Portuguese Famaval satellite dish to ensure reception of ITV2.

ITV2 is only available on one frequency and one frequency only.
Frequency 10758
Polarisation V
Symbol Rate 22000
FEC 5/6
ITV2 is available free to air, with no sky viewing card.

There is also ITV2 HD available.
Frequency 11758
Polarisation H
Symbol Rate 29500
FEC 3/4
And will be availble on your Sky channel list.
ITV2 HD requires a Sky HD subscription.