My boyfriend writing me a sponsorship letter?

Hi,

I am British but currently studying in South Korea. Unfortunatly I wasn't told about the new registration date and may have to register again as a new student. The only problem is, all my most up to date bank statements are all at home which is what I needed as proof for my own financial support. However, they will accept a sponsorship letter from a working resident. My boyfriend of 2 years has offered to do this for me. Will he be allowed to do this? I have all the funds, but non of the proof. Does anyone have a sample of how he should write the letter saying he will be my sponsor?

Thanks =)