How to schedule service with fixed parameters

I write a customized flow service (include REN command for specified needs)based in VAN.VANConnectivity:putToVAN service, so I’m able to sent files to the VAN (Sterling Commerce) without problems.
Now I need to schedule the service to run automatically and need to setup the fixed values for the inputs variables. I try to use the document reference as input with Hardcoded values but dosn’t work, someone can guide to the required steps to accomplish this task?
I need to drop inbound variables somewhere?

You can use the service pub.scheduler:addOnetimeTask to create a scheduled task. In this service, you can specify the scheduled service as well as its inputs. So you can use your own wrapper over this service to make it flexible.

The scheduler in IS Admin screen does not allow you to specify the inputs for the scheduled service.