I'd suggest user the user list and access levels instead of a text file.

User list might contain:

CanUse:*!*@111.111.111.111
CanUse:*!*@222.222.222.222

Etc.

Then your on TEXT would be:

on CanUse:TEXT:*:#: { }

You can, of course use some name other than "CanUse" or just use a number instead of a name for the level.