if you look on the bindings panel there is a bindings group for your cart, you can use this binding group to find the coorect code to referance any of the eCart columns.
For the ID column:
<?php echo $<yourCartName>->DisplayInfo("ID"); ?>
where <yourCartName> is the name of your ecart object.
what is the purpose of creating this recordset? you are going to run into some hurdles doing this. The recordset will need to be in a loop to look up each item id that is in the cart:
php:
while (!$<yourCartName>->EOF()) {
<recordset here>
$<yourCartName>->MoveNext();
}
$<yourCartName>->MoveFirst();
