Please read the help files or follow a tutorial on scripting instead of asking such basic questions.

For example, the command scripts. Instead of using a single topic named "commands", use $chan or # to create a list of commands available only in a specific channel.

Code:
on $*:text:/^!commandadd !?(\S+)/iS:#:{
  if ($nick !isop #) return
  msg # Successfully created $regml(1) $+ !
  writeini commands.ini commands $regml(1) $$3-
}

on $*:text:/^!(\S+)/:#:{
  if ($nick !isop #) return
  if ($readini(acommands.ini,n,commands,$regml(1))) msg # $v1
}


Code:
on $*:text:/^!commandadd !?(\S+)/iS:#:{
  if ($nick !isop #) return
  msg # Successfully created $regml(1) $+ !
  writeini commands.ini # $regml(1) $$3-
}

on $*:text:/^!(\S+)/:#:{
  if ($nick !isop #) return
  if ($readini(acommands.ini,n,#,$regml(1))) msg # $v1
}