It makes it easier if you promote or distinguish the field.
1 – Promoted:
myVar = msgAbc(xxx.xxx.CustomerId)
You will get intelliesense, xxx.xxx will be your namespace.
2. Distinguished
myVar = msgAbc.CustomerId
3. If you don’t have promoted or distinguished field, use the Xpath function:
myVar = xpath(msgAbc,\”string(//Customerid)\”)
Note: the xpath can be complex. You can copy it from your schema (click the element, then go to the properties window). You might have something like this: //*[local-name=’Customer’]/[local-name=’CustomerId’}