Commands in mvvm and c#

What I understood is. you are trying to develope a website without using the mouse.

In this way if you enter any text in textbox and want to search any value(Assumed) then you need a button to click to fire the event.

so in this way. in my knowledge you should use jQuery button codes. as you might know that the buttons clicked can be identified by jQuery code.

below is just an example of enter key pressing on text search.

$('#txtSearchProdAssign').keypress(function (e) {
 var key = e.which;
 if(key == 13)  // the enter key code
  {
    $('input[name = butAssignProd]').click();
    return false;
  }
});

so key==13 is for Enter, in this way you can find for other keys
use this LINK for key reference and put the If condition and make your own commands.

Hope this helps