Strange Question about Stickers

Hello all,

I'm working on an application where I'm required to stick a literal "Sticker" on an arm that's able to rotate. If you can imagine something like putting a band-aid on your arm (think how the band-aid conforms to the shape of your skin), this is the kind of action I need. So far what I have done is

1) mouse click action to pick up sticker from UI

2) a copy of the sticker follows the mouse cursor which is essentially hovering over the arm

I now need to click on any particular place of the arm and have the sticker attach itself. I was thinking something along the lines of using a raycast to see if I get a hit on the arm I've created, and if it does hit you can go ahead and place the sticker on the arm. I suppose the big question is how to transform the sticker so that it actually conforms to the arm? And also attach it to the arm so that when the arm rotates the sticker will rotate relative to the arm? Any help is appreciated.

(p.s. i'm very new to unity if that makes a difference)