Here is a slightly modified version based on forrestcupp post to make it work on kubuntu 12.04:
• Go to your home folder then press Alt-. to see the hidden files then go to .local/share/applications
• In the applications folder right click-->Create New-->Link to Application.
Click the application tab and in the name field enter the desired name of the file for example ‘Microsoft Word 2007’ and in the command field enter
and click OK.
playonlinux --run "Microsoft Word 2007" z:%f
• Go to ~/.PlayOnLinux/shortcuts and right click on the file ‘Microsoft Word 2007’ then open with then Kate.
• Replace located at the end of the file with
and DO NOT LEAVE OUT THE QUOTES.
"$(echo "$@" | sed -e 's:/*/:\\:g')"
• Now right click on the file you want to open with word 2007 then properties then click on the wrench icon then click add. You should find the ‘Microsoft Word 2007’ file you created before under the ‘Lost & Found’ tab.
• Click OK and you are done.