p.s. I am working with CS3
what about looping through all texts, then loop through it's tables, and search the table.
var YourTable = app.activeDocument.texts[i].tables[j] (or something)
then look for
there is a way to use one of the scripts (the findchangebylist.jsx one) to make chained queries almost like macros in word.
have a read of this thread on indesignsecrets.com:
otherwise check out Kasyan Servetsky's find/change by queries:
or this effort from automatication