If your moving i doubt you will get to keep the same number. Try contacting your supplier, but im 99% certain you wont be able to keep it.
The only other way i reckon is this ....
The people who move into your old house may get your number. If you offered to pay for the line, bill and re-direction they may take you up on this.
If the phone provider cant do it and the new owners wont, then im sorry to say you have lost it.
Thats the reason ive had an internet phone line... i will never loose this number even if i move country.