Help requested with inventory item search

Here I am again, with another search problem :-)

I have 'multiple vendors' enabled.  I'm trying to create a search that will give me one row per inventory item with the preferred vendor as one of the results.  Unfortunately, once I add the preferred vendor, I guess a SQL join gets done on the list of vendors for that item, so I get one row for each vendor of an item (for example, if item "stuff" has three vendors, then I'll get three rows output, with the preferred vendor output on each row).  What I think I need is a "mainline=T" for the item record, or access to the