Creating gbp/sgd

[Ondrej Smith]

Hello traders,

 First at all, my English is not the best so forgive me any mistakes you can find.  

I need a little help from you. I want to buy GBP/SGD but my broker does not have this pair. I was thinking about creating it by GBP/USD and USD/SGD.  I need to know, how to do it - which pair and what volume buy/sell if I want to buy 0.2 lots GBP/SGD.

Thanks for all your help.

Ondrej