advancing the "next" workitem ID to a specific number?

I am migrating a large number of workitems from JIRA into RTC using the RTC java client library.   After the migration, the development team will need to use both JIRA and RTC for a certain period of time and want to avoid any overlap between the workitem IDs in the JIRA and RTC systems.   This will help prevent confusion in the team when referring to workitems by their ID.

One way to accomplish this would be to advance the "next" workitem ID to a certain number in RTC before the migration by creating and immediately deleting (archiving) workitems.   But this will leave behind a lot of archived workitems in RTC.

Can anyone suggest an alternative approach to advance the "next" workitem ID in RTC without creating/deleting workitems?

Thanks in advance.