What can be accomplished with the OS Selector in DD 10?

I am visually impaired and find it very difficult to search forums. For those of you who have seen this question many times before, I apologize.

I currently have existing installations of Windows XP Pro (on an SSD)
and Windows 7 Ultimate x64 (on a conventional HHD). The use of Windows 7 is still somewhat experimental in nature.

At any point in time one (and only one) of these two drives is physically connected to the machine (i.e. the unused drive's power plug is unplugged. Each disk has two primary partitions -- the "active" partition installs as C: and the other as D:. The unplugging ensures that there is no possible interaction of the two active partitions.

The two 10 GB D:\ partitions are virtual mirrors of one another and are synchronized (using Acronis B. & R. 10) when necessary.

What I would like to accomplish is, while having both drives plugged in, to use the OS Selector in DD 10 to share the inactive D:\ partition on the SSD with whichever operating system that is currently booted while rendering the "unused" active partition absolutely invisible to the currently booted operating system.

Is this possible?

From my understanding of what happens, I presume that the SSD on which DD 10 is installed will need to be the "first" drive in the BIOS boot order. This presumption is only important as a test of my understanding of the process. Am I totally off base?

Because of my impairment I would appreciate that responses e-mailed me to:Steve@Behman.US

Thanks