Price quota criteria for spread orders

Imported from previous forum

[ original email was from Henrik Johansson - henrik.johansson@neonet.biz ]
How do I specify a spread order with 4 legs as below:

Sell 72 000 STOCK_A / Buy 8 000 STOCK_B
Buy 34 000 STOCK_C
Buy 2 000 STOCK_D

when the price quota criteria STOCK_A / (0.1STOCK_B +0.5STOCK_C +0.04*STOCK_D) >= 1.05 is met

Many thanks,
Henrik