du kannst doch einfach den Text in ein String einladen
dann zerteilst du den String mit dem Befehl hier:
Returns a substring of a string or a segment of a dynamic array.
Unit
System
Category
string handling routines
function Copy(S; Index, Count: Integer): string;
function Copy(S; Index, Count: Integer): array;
Description
S is an expression of a string or dynamic-array type. Index and Count are integer-type expressions. Copy returns a substring or sub array containing Count characters or elements starting at S[Index].
If Index is larger than the length of S, Copy returns an empty string or array.
If Count specifies more characters or array elements than are available, only the characters or elements from S to the end of S are returned.
Note: When S is a dynamic array, Copy can only be used as a parameter in a call to a procedure or function that expects an array parameter. That is, it acts like the Slice function when working with dynamic arrays.
Delphi-Quellcode:
//Pseudocode:
neuerstring:=Copy(meinText,1,einfuegposition)+einfuegtext+copy(meinText,einfuegposition+1,length(meinText)-einfuegposition-1)
Mit dem -/+ 1 musst du nochmal genau nachgucken...