How do I add additional parameters to a jobRequest.xml file?

Issue

Per section 16.8 of this documentation, you can use a REST API to fire off new jobs:

https://access.redhat.com/documentation/en-us/red_hat_jboss_bpm_suite/6.4/html/development_guide/realtime_decision_server

The example [POST] New Job has the following as an example jobRequest.xml file:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<job-request-instance>
    <job-command>org.jbpm.executor.commands.PrintOutCommand</job-command>
    <scheduled-date>2016-02-11T00:00:00-02:00</scheduled-date>
    <data />
</job-request-instance>

We need to call the LogCleanupCommand, and we need to pass a number of additional parameters as part of the call (NextRun, OlderThanPeriod, etc.) Where in the above XML structure should these parameters be included?

We have already tried the following syntax, but it does not seem to work:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<job-request-instance>
    <job-command>org.jbpm.executor.commands.PrintOutCommand</job-command>
    <scheduled-date>2016-02-11T00:00:00-02:00</scheduled-date>
    <data>
       <OlderThanPeriod>60d</OlderThanPeriod>
    </data>
</job-request-instance>