I know right I don't think a bass pedal will be as needed my piano is 88 keys. 
What you reccomend? I'm open to suggestions! My digital piano dose not
have a pedal input.  
 
thank you
 

If your piano does not have an expression pedal input, a MIDI expression pedal may be the only way to go. One solution is to use a resistance-to-MIDI transducer like this. You can then plug any generic expression pedal into it and it will translate pedal movements into MIDI cc11 events.
 
The downside to that approach is that now you've used up your only MIDI input for the expression pedal, so you can't control the piano from SONAR when the pedal's plugged in. The solution to that is called a MIDI Merger, a device that accepts MIDI data from two sources and interleaves them into one output. 
 
So altogether you're looking at $40 for the pedal, $70 for the merger and $150 for the translator. I'd check Sweetwater or zzounds for prices, though, as they're probably a little less than buying direct from the source I linked to above.

I look at that but wasn't sure if that would had work thanks for clearing that up. 
As for Sonar I'm not using that at the moment to record and my piano also got usb/midi. 
I also would record audio not midi.
 
I'm thinking of buying the yamaha fc 7 expression pedal. Got lot great reviews.
But I'am confuse the yamaha pedal reads that it control volume
but nothing on expression or am I miss understanding?
 
Thanks 
 

The FC-7 is an analog expression pedal, meaning it's just a potentiometer in a box. You must have an actual expression pedal input on the piano for it to work. Look at the jacks on the back of the piano. If it doesn't have one labeled "Expression" (or maybe just "Exp.") then the FC-7 won't work by itself.
 
BTW, what model is your piano? (Should have asked that at the top!)

It's good thing I didn't order it. Thanks I was confuse on how this works.
This is my 1st expression pedal to control volume for organ.
 
I try buy Acoustic organ but people magically sold them the day I ask.
Than I found some very nice electronic ones but they were sold too.
 
The upside is I can play organ and or piano doing it this way.
Without finding a space for new instrument lol  
I'm still working towards the Roland pk 9 because it gives more organ feel with the pedals.
 
My digital piano is William digital Piano. 
http://www.williamspianos.com/products/symphony.cfm
 
here the manual page 36 midi imputation 
http://www.williamspianos.com/products/7817_Williams_Symph_Manual.pdf
 
Thanks

Will this work? http://www.sweetwater.com/store/detail/PedalExp/
 
And could I add the pk 6 later? For more organ fill. 
 
Thanks

I have that M-Audio pedal. Or, more precisely, I have a broken non-functioning one in a box. It's pretty flimsy, so I wouldn't recommend that one. It's why I have the Yamaha FC-7 currently on order, which I'm hoping is more rugged. But yes, if you had an expression pedal jack on your piano that pedal would have worked.
 
Unfortunately, you don't have a jack for an expression pedal on that instrument. Therefore, the only way to get an organ swell pedal going is by getting the transducer I linked to above, and plugging a pedal into it.
 
 

Which pedal should I get with the midi solution pedal connector?

I sent Williams piano company email here what they said
 
The pedals on the Symphony are made to act the same as regular piano pedals, so none of them can take the volume from all the way down to all the way up like a guitar volume pedal would. Here are a couple recommendations if that is what you are hoping to do:

http://www.musiciansfriend.com/amplifiers-effects/rocktron-hex-expression-volume-pedal

http://www.musiciansfriend.com/accessories/yamaha-mfc10-midi-footcontroller

I look up Roland pk 9 manual. The $1700 not worth it for my piano. 
The pedalboard keys will work but the expression/volume pedal dose not because its analog. 
So I'll be spending more money just to use it...no thanks.. 
 
Marcus