Virtual Midi Keyboard

OK I'll bite.

FWIW I've never had much luck with Midi Yoke either.

This Virtual Midi Cable will give you 4 virtual ports, will work on any OS (32 bit only)

http://www.maplemidi.com/MapleVMCv356.zip

This one will give you one port but will work on a 64 bit OS too.

http://nerds.de/data/setuploopbe1.exe

This midi keyboard will work with either.

http://www.granucon.com/vmk.html

Lets keep it simple so uninstall midi yoke and ox first. 

Install either of the virtual midi cables above, whichever suits, remember they will be useful for routing midi between apps or within Sonar when you get a proper keyboard too. (I use the Maple VMC for different things all the time so I know it works well with Sonar.)

You may have to reboot at this point for the new midi ports to become available to the system.

Open Sonar, select  the Midi port(s) for the VMC in Sonar's midi device to make them available within Sonar. Close Sonar

Install the Virtual Keyboard and route it's output to your preferred virtual midi port.

Open Sonar, now if you insert a soft synth and select your midi port as the input for the midi track and the output going to the soft synth you should hear the soft-synth being triggered by the keyboard.

Now save up very quickly for a proper keyboard as this setup will drive you nuts in short order, although it can be handy for making edits say on a laptop if you are on the move.

Something like an M-Audio Oxygen 8 is a cheap starting point.