Covers how to set a field on ServiceReq based on what has been selected in the parameters, allowing the switching of ownership through workflows.
In general, link fields require the RecID of the source object to be correctly validated.
You can pass the customer's RecID to the 'Contact Link' field via an update block in the workflow to accomplish this.
The update block will correct the ProfileLink (Contact Link)
1. Select the desired picklist (Red). You will also need to expose the RecID or 'Record Identifier' as an additional field (Blue). Fig 1
2. Add an additional field that will store the RecID of the customer that has been selected.
Configure the field to be set based on a trigger (Blue).
Drag in the additional field exposed in step 1 (Red).
This field can be read-only and hidden to prevent any manual changing (Yellow). Fig 2
3. An update block will allow you to set the value. Fig 3.