OK, thinking on the fly here (just to make a change!) you have a couple of options, first off is to find the relevant phrase:
1) Use the indexOf command (or lastIndexOf) to find it. This works something like this...
myString = "Hello my name is PetitPal";
myIndex = myString.indexOf("my"
;
This would return the value 6 in myIndex, which is the position of "my". The only problem with this method is that if the phrase appears twice, it will only return the first instance, or last if you use lastIndexOf. The bit you're searching for could also be part of another phrase (e.g.: Searching for 'here' and the word 'where' is in the string).
2) The second, more techy option, is to treat the string as an array an work through each character until you find the phrase. I was going to try and write out the functions but I don't have time today (work, eh?) so have a go and if you can't do it I'll try and get it done soon!
You can use the command...
x = <myString>.charAt(<pos>);
... (where <mystring> is the string and <pos> is the character position in the string) to read characters out of a string.
Now, assuming that you have found your phrase, all you need to do is change the letter; if it is just a case of changing a letter for a letter you can use the charAt() command to set the character (I think...), e.g.:
myString.charAt(6) = "W";
If you need to insert a letter I suppose you will have to copy from the string into another one, e.g. ...
myNewString.charAt(i) = myOldString.charAt(i);
...until the point where you need to insert your letter, in which case put it in then continue copyign between the strings.
Anyway, a lot of this is speculation, many many appologies for not being much clearer; just got lots to do at work! Augh!
Good luck and give me a scream (or someone with a little more clarity!) if you need any pointers!
X-)
PetitPal.
