http://www.messagenet.it/gratis/ get a free italian number.
Go to pbxes.com and get a free account.
Register your voip number in pbxes.
Use a betamax provider to forward you italaina voip number to your +44 mobile number. You should be able to find a betamax provider for around 10 cent. So for around 10 eurocent your call will be forwarded to your +44 mobile.
You could also add more free voip numbers from different countries and also forward these to your mobile.