list of all the materials with same base unit of measure and assign them

Hi qm experts,

I have this issue..how would I assign all the materials with same base unit of measure to one inspection plan..if there are 20,000 raw materials that need to be assigned..i want to assign all that materials easily to one inspection plan..could anybody help me??thanks..is there any mass assignment of that materials to one inspection plan??is there any tcode for tha??