How do I make a new column in a .dat file?

How would I go about this, I don't know why but im having trouble with it, is it even possible to do?

[Walter Roberson]

There is no standard for what all .dat files should look like. The .dat file extension is used by any program with any internal format that it finds convenient.

However some programs create .dat files that are reasonable to process. We would have to know more about the one you are using.

[Matteo Pellegrini]

Thank you so much Walter, I'm going to ask another question regarding this if you want to jump on that as well I would absolutely appreciate it, thank you once again

[Walter Roberson]

you should probably continue here instead of asking a new Question