Programming :: Objects And Assignment In Interpreter?

I have it so that an Env object contains all the variables in the current scope, and the parent scope. You can also save them to variables like objects, and my idea is to use the "." operator to get values from them.

First, how do I assign to them? I currently have it that only a variable name can be assigned to, but you should be able to assign to an "obj.value" expression, too. How do I keep track of what variable to set and still be able to say it in an expression and have it evaluate to the variable?

Second, these object don't really have a "type", they're just containers that contain any values you want under any name you want. How can I, for example, define a primitive "boolean" object and have things like if statements recognize it?