This workflow activity is pretty awesome. You can write C# then set a number of different outcomes based on your own custom logic. Pretty sweet. However, Orchard tokenizes your input prior to execution and since tokens are defined using {mytoken}, your C# code will probably get messed up. The solution is to let Orchard's token engine know you need curly braces left alone by adding // #{}. This tells Orchard that tokens should be in the format #{mytoken}.