Yes, this is surely possible because the graphics created with the Drawing Tools is just a normal Graphics
object. Let me give you an example. I made a new drawing and assigned it to a variable:
![Mathematica graphics](https://i.sstatic.net/Mp64S.png)
Now I can work with img
in the same way I would do it with other graphics. For instance you could look at the code you have created:
InputForm[img]
(* Graphics[{Circle[{0.9027777777777779, 0.1972222222222222},
{0.26527777777777783, 0.13611111111111107}],
{EdgeForm[{GrayLevel[0.], Opacity[1.], AbsoluteThickness[1]}],
FaceForm[Hue[0.5, 1., 1.]],
Style[Rectangle[{0.17222222222222228, 0.8083333333333333},
{0.6375000000000002, 0.41388888888888875}],
RectangleBoxOptions -> {RoundingRadius -> 0}]}},
ContentSelectable -> True, ImagePadding -> {{0., 0.}, {0., 0.}},
ImageSize -> {480, 360}, PlotRange -> {{0., 1.3333333333333335},
{0., 1.}}, PlotRangePadding -> Automatic] *)
And of course you can manipulate everything for instance by replace parts of the graphics:
img /. Circle[pt_, r_] :> {FaceForm[Red], Disk[pt, r]}
![Mathematica graphics](https://i.sstatic.net/PmaBp.png)