design of rectangular patch using ie3d

hello friend i have to design this patch using ie3d. i have to cut out the black shaded part from the rectangle as i m just learning ie3d thats why dont know to cut the shaded part. plz someone help me in this i wil b very thank full to u

Open Mgrid
1) Go to Entry>Rectangle
Draw Patch
2) Go to Advanced Edit> Dig Rectangular hole
Dig a big hole
3) Go to MEntry>Rectangle
Now draw internal patch

i m very much thank you my dear friend really grateful to u
and hoping for further help in future