Da%=Instr(Text$,  "{" , SuchAbStelle%)

Text$= Left$(Text$, Da) + NeuString$ + Mid$(Text$, Da2%, -1)

;ozzi789 / Blitzbasic / 12.3.10
;insert txt between is a function that lets you replace a text in a string that is surounded by one or two diffrent signes
;usage:
;insert_txt_between$(Text_you_want_to_edit$,New_text$,firstsign,secondsign)


txt$="left part{old part}right part"
replacetxt$="new part!!"
newtxt$=insert_txt_between$(txt$,replacetxt$,"{","}")
Print newtxt$

WaitKey 

Function insert_txt_between$(ftxt$,ntxt$,sign1$,sign2$)
	pos1=Instr (ftxt$,sign1$,1) ;Detect how many Characters are left of Sign1
	pos2=Instr (ftxt$,sign2$,1) ;Detect how many Characters are right of Sign2
	pos2=pos2-1 ;We want the Sign2 also in the String
	Local leftpart$=Left(ftxt$,pos1) ;Copy the Left Part of the String (with Sign1) into leftpart$
	Local rpos=Len(ftxt$)-pos2 ;Calculate where the right part starts (full lenght- Sign2 Position)
	Local rightpart$=Right(ftxt$,rpos);Copy the Right Part of the String (with Sign2) into rightpart$
	Return leftpart$+ntxt$+rightpart$ ;Return the left, the new text, and the right part
End Function 

Left(Text$, "{", Da%)

Datei = OpenFile("test.txt")
DateiZwei = OpenFile("test2.txt")
ReplaceTxt$ = ""

While Eof(Datei)=0
   Txt=ReadLine(Datei)
   newTxt$=insert_txt_between(Txt, ReplaceTxt,"{","}")      
   WriteLine DateiZwei, newTxt
Wend
CloseFile datei
CloseFile dateizwei
End

Function insert_txt_between$(ftxt$, ntxt$, sign1$, sign2$)
   pos1=Instr (ftxt$, sign1$, 1) 
   pos2=Instr (ftxt$, sign2$, pos1+1)
   pos1=pos1-2 
   If (Pos1=0) Or (Pos2=0) Then
       Return ftxt
   EndIf 
   Local leftpart$=Left(ftxt$, pos1) 
   Local rpos=Len(ftxt$) - pos2
   Local rightpart$=Right(ftxt$, rpos)
   Return leftpart$ + ntxt$ + rightpart$
End Function