Is the file an Excel file? If not then what you propose is very unlikely to get you any further forward (and the Perl component of the solution is not obvious). If the file doesn't render well treated as text then it is likely that the format is too complicated to guess at - have you a specification for the file format?

Unless someone just happens to know the format of the file you wish to manipulate, you will have to provide more information than you have for us to provide much help. We can point you at open and the various other Perl tools that you may need, but on their own that's not going to get you much further forward either.

The next move is yours - find out the file format, write some code, come back here if you encounter problems with the Perl aspect of the task.

    I was thinking if I can open this file in excel...

I'd recommend against doing this. Excel has a nasty habit of rearranging the contents and adding a bunch of extra junk into the file. At least it does on Windows when messing with XML files.

    I can open the file in terminal but it doesn't show up nicely.

My guess here is that either this is a binary file (an example is a .jpg file) or has some encoding that your 'terminal' is not using/expecting. As GrandFather has pointed out, you probably need to find out more about the file format and provide that information before others can offer suggestions on how to read the file.