You can save the complete data and settings, and then load them from your saved file.
Fixed width (or flat file) is column oriented data where each field starts in a certain column and is a fixed length.
For each field, you must enter the position (starting at 1), followed by the field length, followed by the field name.
This can be repeated several times. See the example below.
See also CSV to Fixed Width
Drag and drop your file or
Define Field Layout
Choose Conversion Format: