You can use an Advanced Positional file to define the structure of your Source or Destination layout.
To create an Advanced Positional file layout:
- Select Advanced Positional from the source data format drop-down list.
- Click
to create an Advanced Positional layout from the source data layout. 
On the Create Layout window, provide the details of the layout. For information about the fields of the layout, click here.
- Click Save to save the Advanced Positional layout.