If your idea can be achieved without much effort, and you came up with it without knowing much about the 3DS architecture, you can be sure it's not possible, if it was someone would have already released it. Now, as for why it won't work, even if you could transfer your fake title, it wouldn't have a valid signature, so the home menu wouldn't show it and you wouldn't be able to launch it without a CFW (But if you had CFW that would defeat the purpose of this "exploit"). It may not look like it, but in theory the 3DS is got a nice security scheme, Nintendo is just... Bad at this.