Am I right to assume this is one long string of output?
You are right about the field limit but usually there are unused fields as you say. They can be ignored rather than mapped.
Someone, somewhere - probably a Database Administrator - should have a documented data structure that you could use. Get the start position right and then typoe in the data size. Use the Field List to adjust start positions if things go wrong.
Could be a pain, as you say, but hoping for a ready made model might, in this instance, be a little too hopeful. It is a bit specific.
yes it is indeed a long string - how long is a piece of string - well in this case very long. I have already started painting the fields and have about 50 complete. I am a little concerned about what fields and number of fields that may be required as some may need to be converted from hex etc and julian dates so this will mean I will have to use up some more of the allocation of 255 fields.
I though getting a template would be a big ask but sure if someone wants mine when I'm done(if ever) I will gladly oblige.
I'm sure anyone who had a model would help out but they may not see the post in time for your project.
It occurs to me that you may be able to extract fields you need to perform calculations on into a seperate extract and do the calcs then link back as a lookup to the main extraction. If that was going to save saved enough fields it might make sense. I would guess a gldet report has good opportunities for creating unambiguous lookup links.
However, if there are only a handful of fields that require calcs you may not have a net gain by the time you have the links created/included.