When converting an activity (such as Phone Call) to case, we can only specify the Customer and the Subject on the popup dialog. What if we want to auto-populate the case details with the information from the activity?
At first I thought we can write a plugin that triggers on the post-create of a case. However this is not possible since CRM creates the Case before it sets the Regarding field on the Activity.
The workaround for this is to create the post-update plugin on the Activity itself. This way when the Regarding field is assigned by CRM, it will look for the Case and update its details.
Be careful though because this might not work when converting Activity to Case from Outlook. I read somewhere that when converting Email to Outlook, the Regarding field is set to the Parent Customer of the Case rather than the Case itself.
Hope this helps,