香港的HSBC BANK的ACCOUNT可以匯款到意大利的IBAN銀行嗎?

Yes, it can
You just need to tell HSBC to send a Telegraphic Transfer for you and provide the information listed below:
1. Receiving Bank's Name (and address, if you have, if not, that's ok, coz the bank address is optional)
2. Receiving Bank's City & Country
3. IBAN Number
4. Receiving Account Holder's Name & Account Number
5. Receiving Account Holder's Address (optional)
6. Currency & Amount

香港的銀行碼係咩? <- do you mean you want to have the HSBC Hong Kong's Bank Code? If yes, then that is 004, but you don't really need this information if you are wiring out the money to other country

yes..you just tell them the bene,information,and provide the IBAN to them