This is done through the Postings:
From the LAD either the Postings will be open already or select New Posting.
Select Payment tab.
Select Disbursement Ledger in the drop down.
Put in the matter reference and then select the Anticipated box on the right hand side of the screen.
Select the Anticipated you wish to incur by clicking on it or ticking the box.
This will populate the boxes with the details of the Anticipated and the amount.
Fill any extra details needed for the payment and select OK/Next.