PAIRS TRADING - 4 ASSETS

I need an indicator that use that formula:

S = A (divide/multiply) B (divide/mulitply/none) C  (divide/mulitply/none) D

Conditions:

a) A, B, C, D are assets (Ex: EURUSD, BTCUSD, PETR4, PETRK232) where A and B are required, C and D are optional

b) To calculate S, we will have last (close) price of A, B, C, D.

c) S neeeds to have until 8 points of float (0.00000001)

d) Indicator have to interact with other indicators like SMA, Bollinger Bands, RSI, etc

e) Indicador can be customized: line color, size line, etc)