Insert Node into XML using XPATH

Hi,

I'm having problems inserting a node into a XML. After getting some attributes from the CRC result i'd like to store them in a temp xml variable.
After that the parent node of the attributes should be inserterd in a goal XML with a repeating node structure.

Whats the right way to set a node to a certain position in the goal XML?

Now the only thing i'm getting is erros about transaction:

Caused by: javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: a307d1e:fd15:4d35c503:1351f50 status: ActionStatus.ABORT_ONLY >
    at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedCo nnection(TxConnectionManager.java:304)
    at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateC onnection(BaseConnectionManager2.java:396)

Etc..

Thx!