Convert Yuan value symbols to USD

IGNORE PREVIOUS SCRIPT/POST (titled: "yuan normiz")

If you like to look add symbols that are valued in China's Yuan and want to convert them to USD accurately then this is the perfect script for you.

"I'm not sure if this script is for me. Does my setup apply here?"
If either of these resemble your chart setup then this is for you:
Example 1: You have COINBASE:BTCUSD on your main chart often add to compare Bitstamp:btcusd and Okcoin:btccny.
Example 2: You have SPY or SPX (or DJIA etc) as your main chart but like to add other composites to compare like SSE(Shanghai Stock Exchange index) to your main chart.

This takes the symbol of your choice (default is BTCCHINA:BTCCNY) that is expressed in Yuan and divides it by the corresponding value of IDC's USDCNH ticker. Not the last value of USDCNH, but the respective tick mark----BTCCNY's close 3 months ago is divided by USDCNH's close 3 months ago.