Unusual chart design - possible?

[Gingertrees]

I've been asked to produce a chart based on sales data for 4 companies, across time. The design that was requested (sketched out for me, in fact) is unlike any I've ever seen in Excel. The idea is to have a bar chart, spanning 12 months time, with this year's data on top, and the prev. yr's data mirror-imaged below. So there would be POSITIVE numbers on both sides of the axis. For each calendar month, there would be a group of 4 bars representing the four companies. I tried to approximate it in the code below:

(the columns of X, W, P, and L represent sales from diff. companies.)
Say that the first column of Jan represents sales of $400 in 2012, $200 in 2011. 
In W, $200 in 2012, $300 in 2011.

2012
Jan                     Feb             Mar            A ...    Dec.
$4  $2    $4  $3        3  3  4  3
X         P                   P 
X         P    L        X  W  P  L
X    W    P    L        X  W  P  L
X    W    P    L        X  W  P  L
----------------------------------------------------------------------
X    W    P    L        X  W  P  L
X    W    P    L        X  W  P  L
     W    P             X     P
          P                   P 
$2   $3   $4  $2        3  2  4  2
Jan                     Feb            Mar             A ...
2011

Is this a possible chart design? How would I create it?

 

[Steve=True]

Hi Ginger Trees.

There is an easy change, but what if the difference is negative?

Would putting a Negative Percentage at the bottom be okay?

Like this?

Let me know.

Steve=True

 

[Steve=True]

Hi Ginger Trees.

I have created a REDO post to add positive and negative labels above your upper columns

http://www.exceldashboardtemplates.com/?p=1433

Steve=True

 

[Gingertrees]

lol wow, two blog posts and videos! It must be a slow week for you. Or I have interesting problems. Thank you ever so much. Thanks to all your help, I was able to deliver exactly what was requested by 2 or more of my bosses. Have a great weekend, Steve=True!

 

[Steve=True]

Wonderful. I am so glad that i was able to help you impress your bosses

Steve=True