Thanks Will. We could use a join and have a huge list of possibilities in a hidden column but have come up with a different solution to this issue where we need to take the result from a search dialog and use it to get a list of IDs from a table not associated with the grid, then use those IDs to filter the grid. We have done this by capturing the $_GET after the search dialog ‘Find’ is clicked. Extracted the relevant data, selected the IDs against this data from the external table and fed it back to the select statement after unsetting the fictitious column from the search filter and feeding the rest back into the $_GET.