I have discoverd a method to get the .pat information you need so you can use store the patterns, rescale them and use them in another software.
basically I exploit the temporary creation of .pat files by revit while it is exporting a dwg.
if you go to a folder on your computer, and change the permissions to deny the delete function when you export a view that has the hatch pattern you want on it the FP_1.pat FP_2.pat....etc files won't be deleted, and then you just need to add the %TYPE=MODEL or %TYPE=DRAFTING after the hatch name.
to do this, right click on the folder.
Select the security TAB
Select your user name.
Click Change Permissions
Then select your user name again
Then tick the Deny boxes next to delete, and delete Subfolders and files
Click OK a heap of times.
Now if you export a view to this folder all the hatch files (.pat files) will not be deleted.
allowing you to steal the code from within them.
Note: I don't seem to be able to control the scale of this export very accuratly.