You can use the Trust Transfer function to automatically move trust funds from one matter to another. The trust transfer posts a trust check on one file and a trust receipt on the other.
Choose the Trust module
Click the Transfer button (to the left of the Trust module button)
Enter the From File Number
Enter the To File Number
Enter the Amount
Enter the Transfer Date
Enter the Reason
Note you cannot transfer funds between files that are assigned different bank accounts. In that case you would need to post an actual check and receipt.