Create new table/rows from extrapolated text in existing table

Hi,

I have a fairly complex (perhaps) issue I'm having some trouble figuring out. I have a datasource (from sharepoint) which has a number of columns, the 2 of interest here are "id" which is numeric and unique, and a "description" type field which is free form text input. Now the "description" field typically will mention a handful of city names. We'll use Houston, Austin, and Dallas for this example. I'd like to be able to use a map visual to filter a table visual based on if that city is mentioned in the description. So my idea is to have a "IdToDescription" table, with basically a row with each id, descrition combo. so incoming data like this:

id             description
----           --------------------------------------------------------
12             Major outage in Houston, as well as Austin this weekend.
13             Minor degradation in Dallas/Austin last night.

ends up like this

id               City
----             ---------------
12               Houston
12               Austin
13               Dallas
13               Austin

and from there I can use relationships to map the ID to city. The issue may be more complicated as some users may use "HN" etc but I can tackle that problem separately assuming there's a decent solution for the one presented.

Thanks