Multiple Images On Top Of Each Other In Table Cell

Hella all,

Is it possible to stack two images on top of each other in a table ?

Let me clarify where i'm going to.
I have a report where in one table i would like to display (in a graphical way) how much a sales person has sold towards
the whole sales amount.
To do so i would like to set my background of my cell to yellow and then use an image (just a green rectangle)
where i adjust the padding according to the percentage.
When i set my background to yellow and i insert my image in the cell, the textbox cell properties disapear and are
replaced with the image properties. So also my background that was defined in my textbox is gone.
Now i was thinking if i could set two images on top of each other (a yellow rectangle and a green rectangle). But when
i do that, one image is replaced with another.

Am i doing something wrong or is there another way to achieve what i want to do?

Greetz
Vinnie