I tried to point you to the function "Convert codepage" and asked you whether that would help you.
Your answer was
Which is different from
As you do not supply a file or a screendump you have to give much more details about your problems.
Or, on a more general level, here is what would make up a nice support request:
As you mention a third party program which apparently does not produce the output that you expect, I would also contact the support of that program and see what they can do.
Once an invalid format has been created, it becomes very tricky to remove the faults.