To customize this, simply replace the large number (23590, or how much one US dollar is in dong, with another number, like how much one US dollar is in rubles.) with your desired number, change the currency name (rubles, euros, won, pounds, etc.) and done! (example: (space)Russian rubles in the join slot)
All by me, use with credit! (thou u could probaly code it by urself, just sayin')