Replace in Own C#

[seer]

Can I/How can I replace only first match on my Own C#?

example:
var before = "want to replace this, but not this";
var after = before..Replace("this", "replaced");
return after

result i want:
"want to replace replaced, but not this"

So basicaly, can I somehow determine match no. for replace?

 

[seer]

I solved this by using regex replace:

var regex = new Regex("o");
var newText = regex.Replace("Hello World", "Foo", 1);