How can we update Project Role on Time cards imported from Oracle Time and Labor

We have a requirement to capture Project roles on a labor cost transaction so that we can perform the customer billing by Project roles.

We noticed that, there is no Project role field in Oracle Time and labor, hence time cards imported from OTL doesnt have Project role field populated.

Need suggestions on how can we update the project role information for OTL timecards? Or is there a way we can make use of HR Jobs to Project role mapping feature. Only catch is Client doesnt have 1 - 1 mapping between HR jobs to Project role. so its possible that person with same HR job may be working with different roles on different projects