It depends how complex the maxcro would be and how many conditions you want. For a few ones you can use e.g.:
{% x=FooValue; if (x=="foo"){"foo"} else {if (x=="foo2") {"foo2"} else {if (x="foo3") {"foo3"}}} #%}
But, if it should be more complex you should use the switch statement or, create a custom macro which will do the logic in the C# code.