Singdon lo lan most probably refers to the Chinese pinyin-style writing for Santa Claus, "shèngdàn l?orén". "Sheng" means holy, "dan" means birth and "laoren" means old man.
"In Chinese, shèng means "sacred, holy", dàn means "birth", and kuàilè is "happy, joyous." So in China, Christmas is a celebration of the "holy birth," in clear reference to its Christian origin."
"Santa Claus is shèngdàn l?orén. L?orén means "old man."
https://books.google.com/books?id=ymW2mBkl-tYC&pg=PA81&lpg=PA81
"Dun Che Lao Ren" (Old Man of Christmas) is Chinese pinyin for Father Christmas.
"Lan Khoong" is what Santa Claus is called in Hong Kong.
"In China, Christian children have an enjoyable time as they painstakingly decorate their homes and trees with paper streamers, ribbons, and cotton wool. Christmas trees are called 'Trees of Light' in China. Chinese Christian children address Father Christmas as 'Dun Che Lao Ren' Which when translated means the Old Man of Christmas."
"In Hong Kong, special Church services are held in the Chinese language for the benefit of the locals. The central theme for Christmas Greeting cards here is the depiction of the Holy Family in an authentic Chinese atmospheric setting. Santa Clause is fondly called 'Lan Khoong' by Christian children in Hong Kong."
