From the edit dialog, you can:

The Edit dialog also allows you to add a new macro id to a command that didn't previously have an associated id (thus turning it into a persistent command), or alter (or remove) the id of an existing command.
Adding new commands to the macro requires that you have some knowledge of the commands. There is a filter above the Available Commands list that defaults to showing only edit commands (based on looking at categories). Some commands are not appropriate to a macro, but it's impossible for me to tell what they are, so you may have to experiment.

Special macro helper commands

The Mark commands are provided as a way to maintain some state while other operations are performed without requiring scripting. For example, to comment a selected area, you could record a sequence of commands like:
    mark selection start
    move cursor right (puts cursor at end of selection
    insert string "*/"
    move cursor to mark
    insert string "/*"