Passing String objects as parameters to a function

Hello All, I am a newbie to C. All I know about it has come from working with Arduino. This is my current hang-up, on which I have worked for hours. I want to be able to pass alphanumeric strings in the form of String objects to a function which does some formatting on it and passes it back in the formatted state. I want to be able to call this function from various points in the sketch with Stings of various names. I'm sure this can be done but I can't figure out the syntax. Basically it would look like this....

String MyString = "some alphanumeric text";

void loop(){
    format_string(MyString);
}

void format_string (String anyString){
   //do some formatting
}

I'd appreciate any help.

void format_string (String & anyString){
//do some formatting
}

Thanks a bunch. That works. Your reply has got to be the all-time briefest successful reply to a query... one character long! No one can beat that. It is an [u]atom[/u] of language. Gives new meaning to, "Let me give you a "bit" of advice. :D

XD