在R中，如何从函数中将新信息附加到S4对象？

I am passing a string that represents a variable name to a function. Essentially I want to add new information to the variable, the problem I'm having is that it doesn't actually attach the new information to the S4 object, it just creates a new variable with myObjName.newinfo that is actually unrelated to the original object. I am passing a string that represents a variabl