Different service levels

Does someone know a program that can calculate the required number of agents in a call center, if all agents are answering calls from several queues with different service levels. This is the usual situation in an outsourcing call center. An example: How many agents are required in my call center to handel two queues (if all agents will answer calls from both ques), if X1 calls are received in the que nr 1 and X2 calls are received in the que nr 2 in 1 houer, and the average call duration is Y1 seconds in que nr1 and Y2 seconds in que nr2, and if Z1% of calls must be answered within W1 seconds
in que nr1 and Z2% of calls must be answered within W2 seconds in que nr2?