Jasper reports server expert guidance required

We have some reports that we generate using jasper reports. The unique merchant codes are hard coded in the report file hence it works only for 1 merchant. We would like to automate the process such that the reports are generated simultanously for multiple clients based on dynamic input (picked from a database and invoked). How can we do that using jasper reports? If we can do this, the application developed can be automated to serve 100s of clients. What is required from you? We need you to guide us on how to automate jasper reports where it allows dynamic values as input.