$didreg
From Scriptwiki
Didreg searches a dialog element for a line that matches the specified regular expression.
$didreg(name,id,regex[,N])
- Name is the name of the loaded dialog.
- ID is the id of the dialog element you are searching.
- Regex is the regular expression to match.
- N is the line to start your search from. If none is given, all lines are searched (default 1).
- Returns: The number of the line which matches the given regular expression.