replace same words in a string with different words

Question

Hi All,

 

I have a string like this:

string s= "it is an \"Auto\" and The \"Auto\" has three seats and blabla \"Auto\" "

i want to to replace Auto with unique numbers, the output should be like this:

"it is an "Auto1" and The "Auto2" has three seats and blabla "Auto3" "

 

Thanks,

Darma