Programmatically press "Left" key in a text input

e = jQuery.Event("keydown"); // define this once in global scope
e.which = 37; // Some key value
$("input").trigger(e);

where "input" is your textarea

37 - left
38 - up
39 - right
40 - down

So when you record your "events" you record the values for the keys pressed.
I'm sure you already figured out a way to do this but just in case, here's an idea of how i would tackle it:

var keysPressed = new Array(); // somewhere in the global scope
$("input").keydown(function (e) {
    keysPressed.push(e.which); //adding values to the end of array
});

Hope this helps

And for those not viewing jQuery as the solution to everything :)

From http://blog.josh420.com/archives/2007/10/setting-cursor-position-in-a-textbox-or-textarea-with-javascript.aspx

function setCaretPosition(elemId, caretPos) {
    var elem = document.getElementById(elemId);

    if(elem != null) {
        if(elem.createTextRange) {
            var range = elem.createTextRange();
            range.move('character', caretPos);
            range.select();
        }
        else {
            if(elem.selectionStart) {
                elem.focus();
                elem.setSelectionRange(caretPos, caretPos);
            }
            else
                elem.focus();
        }
    }
}