Something like this you mean?:
Code:
/personal.input {
  unset %personal.input
  var %personal.input $$?="please enter your personal info"
  if (%personal.input !== $null) { /writeini -n preform.ini personal input %personal.input }
  unset %personal.input
}

The -n makes mIRC attempt to write to the ini file even if it is greater than 64k in size
(look at: /help /writeini)

Hope this helps?!

Aubs.
cool