Code To Replace String, Replace("string", The3thcharacter,"*")?

Compositing
1

what's the code in C+ (shake code) that to replace a single words to a text,

say,

string Text1 = "ABCDEF...................................................."

i want to replace the 10 character in string Text1 to say *, how?

i know i can use the strlen, and something like "ABCD... " +"*" + "..........",

but is there any 1 simple code to enable us replace a charater everywhere in a string,

something like, replace("string", the3thCharacter,"*")

cause i am creating a macro, but get stuck here.

thanks