I have taken the similar approach for one of my requirement wherein i have created the custom object with all the parameters in it and associated the process with the object.
When user selects the parameters and save it at the object instance, process takes the same and generate the output accordingly.
For Scheduling purpose, i have created one instance with the fixed parameters and one Stand Alon process, where i am taking the parameters from the predefined instance of the custom object.
Though it is not the very good approach but it serves the purpose.
Thanks,
Manish