This can be done, but I must ask this key question: Are you sure you should have all these values in one field instead of a set of related records with one value in each record?
Such a data model would greatly simplify what you are trying to do here.
- Set Variable [ $Cursor; Value:Get ( ActiveSelectionStart ) ]
- Set Variable [ $Start; Value:Max ( Position ( YourTable::Field ; ¶ ; $cursor ; -1 ) + 1 ; 1 ) ]
- Set Variable [ $End; Value:Let ( E = Position ( YourTable::Field ; ¶ ; $cursor ; 1 ) ; E + not E * ( Length ( YourTable::Field ) + 1 ) ) ]
- Set Selection [YourTable::Field ; Start Position: $Start ; End Position: $End ]