Hi,
normally it shouldn´t be a big problem to add a hand deco.
If you look at your valve cover, there is a lever for the decomp which is activated by the kickstarter mechanism.
In up direction you can put another cable to this lever and fix an additional lever to your handle bar.
If you want to, you can change your whole clutchlever (attachment) and replace it with a KTM part. The LC4 had clutch and decomp lever at one attachment. That´s nicer. Maybe you get a used one for little money.
greetings
hribman