You can prepare fixed-width positional text files, often known as extracts, by using the SAP Query tool.
Before creating any extracts, you need to be sure that you have a formal spec to work against.
You should always change the format and column width on the Title Format screen when creating extract files.
You can never change the width of a currency, date, or time field.
Microsoft Notepad is a good tool to use when checking to make sure you have properly created positional extract files.