Make wine program as a default program

This instruction is taken from Ubuntu Wine documentation. I use this to link PDF files to PDF-XChange (,which work flawlessly with PDFs to highlight, comment, bookmark, etc). Note that portable version didn't work with this method.

Creating file associations
If you want certain files to open in a windows application by clicking on them, the best way is to create a script. For example I want Adobe Flash project files (*.fla) to open in Adobe's Flash editor if I double click it.
You can for example create a file using this terminal command.
gedit ~/.wine/Flash\ 8
Now paste the following example script in it, save and close gedit.
Example script:

#!/bin/sh

QUICKPARLOCATION="c:\\Program Files\\Macromedia\\Flash 8\\Flash.exe"
PARAM=`winepath -w "$*"`
wine "$QUICKPARLOCATION" "$PARAM"
exit 0

Make sure the file is executable with this command.
chmod +x ~/.wine/Flash\ 8
After you completed this go to an *.fla file right click it, properties, go to the “open with” pane, click add, add this line into your terminal and select the radio button.
'/home//.wine/Flash 8'
Now if everything went ok, you can doubleclick the file and it will be openend in Flash 8.