mini displayport to dual DVI interfaces for iMac 27" mid 2010

[forrestgumpx]

The minidisplay port of the mid 2010 iMac 27" model is bidirectional.

I am wondering whether there are mini displayport cables which has dual dvi interfaces, so not minidisplayport-to-single DVI. but:

minidisplayport
|
|
/\
/ \
/ \
/ \
/ \
/ \
(female) (male)
DVI input DVI output

This in order to hook my PC LCD as 2nd monitor (extension) to my iMac but also to input my PC to my iMac 27" screen. from time to time.

--edit---
great the ascii spaces are ignored... but you get the idea...