Different definitions for the same record format

Hi!

I want to convert a S/36 file to a file with a DDS. The problem is: for the
same record format, there is 3 different way to define the fields, depending
on the record identification code. Is there any way to create a physical
file that wil contain the 3 different ways to define the fields for the same
record format? If the record ientification is, for example, A, I want the
record format to be defined like this:

1         1 Code
2       31 Name
32    362MNT

but if the record identification code is C, I want the record format to be
defined like that:

1         1 Code
2       100JulDat
11     180RegDat

Any example of a DDS file allowing to do that?

Charles St-Laurent