TScrollBox Questions

hello fellow delphi programmers,
i want to draw an object on the scrollbox. i could use a Tshape but the
scrollbox onmousemove proc doesn't work when it goes over the Tshape. i
need to know how the tshape can remain visible but it does not cover the
scrollbox so the mousemove can work. i hope i've made some sense
thanks in advanced, jkidik :))