I'm using the awesome FaderPort controller with Sonar.
 
I'm wondering how I can easily and temporarily set the fader to control a tracks send level to record automation. Is there an easy way to reassign the fader just during an automation write?
 
Gavin

Hopefully you'll get a direct approach from somebody.  In the mean time, here are a couple of ideas that I have NOT tried myself
 
1)  Send to an Aux Track (at 0db) and automate the AT level, routing the AT to the intended destination
2)  Same as (1), but copy the automation back to the send lane once you have it recorded instead of directly routing.  Then delete the AT.
 
If you are using AZ Controller, you might be able to something more direct by utilizing SHIFT

https://www.youtube.com/watch?v=N3SX2eIc88k  Here is a technique I came up with when I was using a mackie controller - I originally wanted to assign a fader to control the send - and saw it wasn't allowed.. so this is what I came up with. Pretty much the same tehnique as illustrated above by BobF