This thread, about cursor not moving, is not the correct place for this question. It should have its own nice new and shiny thread, to avoid causing confusion in the existing thread, and to enable it to get the attention that it deserves. (And a good title, of course, which means a relevant title. Something like "Making my own command, copyconv" perhaps?
Anyway, the easiest way to do that is to include the script (it is a script, eg a Bash script, isn't it?) in a directory that is in your path. Usally, that would be a directory such as /home/your_username/bin, but the exact path doesn't matter so much, provided that
- it is in the path for the user(s) who will use it
- the user(s) who will use it have execute privileges
It may be the case that you really want an answer to the question "How do I make dd do something that it doesn't currently do by default (or, do, by default, something different)?" It is probably easiest if you give some clue about what this other thing might be, but in any case a look at the man page for dd could be helpful, if you haven't done that already.