its posible but would take hand coding.
you would need a recordset to return the maximum quantity field, then hand code a loop to go from 1 to the max.
for example:
$max=$row_recordsetName['MaxQTYColName'];
for($i=1;$i<$max;$i++){
echo("<option value=\"".$i."\">".$i."</option>");
}
if you need help setting this up, we can help through a premiere support appointment:
http://www.webassist.com/premier_request.php