Välj objekt som poster från en kolumn i en annan tabell

Har du testat något liknande

SELECT pst_qty AS [QTY] 
  ,[MFGPN] 
  ,[mfg_name] AS [MANUFACTURER] 
  ,description 
  ,sup_id 
  FROM [foo] 
  INNER JOIN [foo2] 
  ON [foo].[MFGPN] LIKE '%' + [foo2].TestString + '%'