compare 2 columns and add stock numner

hi,

I have 2 sets of data in the attached file
what I would like to have is the stock number in column "g" also in column "e" were the materials are equal in column "h" and column " c"

the material repeats itself in column in column "c" as there are about 11000 lines yet in column "h" it will only be once as there are less lines

thanks for you help
steve