From Xojo Documentation
Moves the FolderItem to the path specified by Destination.
It does a move rather than a copy even when the source file is on another volume. After the move, the original file no longer exists. See the example of MoveFileTo in the Examples section for FolderItem. If there is an error, the LastErrorCode property contains an error code.
This example uses MoveFileTo. The source file will be deleted and moved into the destination folder.