I am trying to create a custom field to add to my Sales order form that would allow me to select from a list of Support Cases. If possible I would like to filter the list of Support Cases to show only cases from the same Customer. The issue I am trying to solve is my Customer Returns team would like to have a link back to an original support case on the Sales Order form if after working a support case they decide they need to create a replacement Sales order as part of the solution to resolve the case.

I have been able to create a custom field that allows me to select other transactions (Sales Order #SO1001, Invoice #INV1010, etc.) but Support Cases are not included in the Transactions list? Any help would be greatly appreciated!