There is not enough information available to answer your question precisely. What plugin is generating this order confirmation page? Your best bet would be to inquire at the dedicated support forum of that plugin.
The most I can tell you without more information is all that data was likely already output by the page template, so the data is available to PHP from the same source. If the template has something like TOTAL: <?php echo $total; ?>, you could in part do &udf2=<?php echo $total; ?> However, if the $total output included currency and thousands separators, that may be incompatible with the pixel code and would need to be parsed out.
Thank you for your response bcworkz.
The plugin I used to insert the pixel is “Add Tracking Code to WC Thank you Page.” The plugin allows you to paste in the pixel which was given to me by SocialLadder. The pixel was not generated from a plugin, a generic pixel was sent to me and they asked me to input the correct variables in the bracketed areas. For instance [orderid] needs to be placed the the variable that will pull the actual orderid when a purchase is made.
OK, sure, but if you supply 3rd party pixel code to the plugin, how are you to set run time variables within the code? That question is best answered by the plugin devs.
The alternative would be to bypass the plugin and place the pixel code directly on the order confirmation page template. Then the variables can be populated by PHP prior to output, as my previous minimal example suggests.
