Seek123:
I just saw yesterday on internet that you can buy soymilk makers to make soymilk at home very cheaply. It is available on USA websites so you would need a converter when you go back but that seems a really good answer to your problem.
Well, you can check out two brands Staeta and Sofit (Godrej) from Reliance Mart on the S.G highway. Probably other supermarket stores like Star Bazaar, Big Bazaar and D-Mart will also have stocks of them. Both are well known brands and are available in different flavors like Apple, Mango, Strawberry, Coffee, Chocolate, Kesar Pista and Natural.