Capture touch path from screen

Hi,

I was trying to find if there is a way to capture the user touched/click-drag path from the screen and then use that path to define a sprite's movement?

Just like then "unlock" feature on the touch screen phones where you need to draw a alphabet to unlock the phone.

Any pointers please? :)

http://www.scirra.com/forum/simple-gesture-recognition_topic45379.html