Need help setting proxys in SIMBA

Hi, I am starting on the RS3 bottling, I have everything already, the method, the script for SIMBA, the accounts, the private proxys, the only thing I need to know is how to set each session on SIMBA in a different proxy. I read in several places how t do it, but it doesnt work at all. Somebody here know how to configure SIMBA so I can run each instance (using MAGIC) with a different proxy in each session?
Thank you