Digi camera or software?

[tamborine]

Anyone know how a color object can be superimposed on a black & white photo/print.

[Milvus]

You will first need Photo manipulations software like Photoshop (expensive) Photoshop Elements (Cheaper) iPhoto (Mac only) or GIMP (Free).
Then you need to select and copy the part of the colour image you want from its picture and paste it onto your black and white image. You open both images in your photo programme.

[rojash]

Depends on your manipulation software and the format of your monochrome image. You may need to convert the mono image to full colour before pasting in your coloured image.

For example, in Paintshop Pro, you would click Image/Increase color depth, and set it to match the depth of your coloured image. Otherwise you may find that your coloured image gets pasted as greyscale.