Hi,
There is an option on the plugin back-end to sort by numeric custom field, that should be the key solution to it. So you could basically create a custom field, add the number there, and then set the ordering by it on the General Options -> Ordering panel.
The additional search tags are stored in a custom field: _asp_additional_tags
But, you can also import the keywords to another custom field as well, and then choose only to search that on the General Options -> Sources panel.