Your Intersango account is a hosted (shared) EWallet. So you can withdraw bitcoins to any bitcoin address, not just your own.
- https://en.bitcoin.it/wiki/EWallet
Some other exchanges have a "redeemable code" / voucher / "coupon" as a method for transferring bitcoins (and sometimes fiat) from one exchange account to another (known as account-to-account, or A2A, transfers). Intersango determined that they couldn't offer that feature, being an exchange operating from the UK.
- http://en.bitcoin.it/wiki/A2A_Transfer_Methods
- http://en.bitcoin.it/wiki/Redeemable_code
So there are no restrictions on what you wish to do with your bitcoins in your Intersango account.
With Bitcoin being a global digital currency, there's no concept of geography or political boundaries. There's no way for an exchange to know where the funds for the withdrawal are being sent.