Obtain Shape-OID's contained in Frames

I have
[*] a sheet opend
[*] the oid of a frame-shape (device, unit, function,...) placed on the opened sheet

I need
A list of all shape-oid's placed in this frame-shape (frame "contains" this shape)

Example
two device-shapes are surroundes by a Unit-Shape. I have the OID of the frame Shape, I need the OID's of the device shape.

Thanks!