How to add multiple CIs on a Change Request Record Producer thru Service Catalog

[QX]

Hi - I am building a simplified change request that will be submitted thru the portal. I am using a Select List and mapping it to the configuration item so the requester can provide more than one CI when needed and getting the error message when submitting. The Change gets created but only one CI is added and not all the once selected. Can anyone advice on how can I accomplish a requester to add multiple CIs thru a service catalog record producer? 

This is the error I get

[-O-]

You cannot accomplish adding to related lists using simple field mapping. You need to script it in the producer script.

[QX]

Thank you, any scripting ideas on how to accomplish this? Scripting newbie here.