If sort can help do this, copy value from one line and put it into another line?
I would like to copy value in col 287-288 from line D and put it at the end of line C, line D is always follow with line C, and there are many kind of other records as well which need to keep the same.
You've already had tasks recently which you should be able to apply to do this.
Think about how you'd do it in COBOL. Then think about what you don't have in SORT, and what you have to do instead. You've already had it, but "going in the other direction". This is the same. You need to get to recognise when you know how to do something.