How do I send params with Uploadify?

I’m trying to replace SWFUpload in WordPress with Uploadify, because it’s seems more customize friendly and easier to work with.

Now, I’ve understand that WordPress sends some data for a server validation when uploading files. I’m curious how I can use this data in my Uploadify form, to replace WordPress’ own upload form.

This is an example of an upload form from WordPress:

<object width="132" height="23" class="swfupload" data="http://xxx.com/wp-includes/js/swfupload/swfupload.swf?preventswfcaching=1300750794560" type="application/x-shockwave-flash" id="SWFUpload_0">
<param value="window" name="wmode">
<param value="http://xxx.com/wp-includes/js/swfupload/swfupload.swf?preventswfcaching=1300750794560" name="movie">
<param value="high" name="quality">
<param value="false" name="menu">
<param value="always" name="allowScriptAccess">
<param value="movieName=SWFUpload_0&amp;uploadURL=http%3A%2F%2Fxxx.com%2Fwp-admin%2Fasync-upload.php&amp;useQueryString=false&amp;requeueOnError=false&amp;httpSuccess=&amp;assumeSuccessTimeout=0&amp;params=post_id%3D3562%26amp%3Bauth_cookie%3Dadmin%257C1301439526%257C5e5e63158e880597c782656a719f1738%26amp%3Blogged_in_cookie%3Dadmin%257C1301439526%257Ce01206ec12b5cee4a605f9abff385cc0%26amp%3B_wpnonce%3Dc52b08b0ce%26amp%3Btype%3Dimage%26amp%3Btab%3Dtype%26amp%3Bshort%3D1&amp;filePostName=async-upload&amp;fileTypes=*.*&amp;fileTypesDescription=All%20Files&amp;fileSizeLimit=4194304b&amp;fileUploadLimit=0&amp;fileQueueLimit=0&amp;debugEnabled=false&amp;buttonImageURL=http%3A%2F%2Fxxx.com%2Fwp-includes%2Fimages%2Fupload.png%3Fver%3D20100531&amp;buttonWidth=132&amp;buttonHeight=23&amp;buttonText=%3Cspan%20class%3D%22button%22%3ESelect%20Files%3C%2Fspan%3E&amp;buttonTextTopPadding=3&amp;buttonTextLeftPadding=0&amp;buttonTextStyle=.button%20%7B%20text-align%3A%20center%3B%20font-weight%3A%20bold%3B%20font-family%3A%22Lucida%20Grande%22%2CVerdana%2CArial%2C%22Bitstream%20Vera%20Sans%22%2Csans-serif%3B%20font-size%3A%2011px%3B%20text-shadow%3A%200%201px%200%20%23FFFFFF%3B%20color%3A%23464646%3B%20%7D&amp;buttonAction=-110&amp;buttonDisabled=false&amp;buttonCursor=-1" name="flashvars">
</object>

Now, I’m guessing this form data gets generated here:
http://pastie.org/private/dxuytcqhu7b9odfhkwug
(Entire code here: http://phpxref.ftwr.co.uk/wordpress/nav.html?wp-admin/includes/media.php.source.html begins around line 1494)

But besides that I’m pretty clueless.
How do I send the needed params through Uploadify? Scriptdata? Which params are needed? Is this even possible?