search for text in colB, starting with next row search for 1st occurrence of specific #

I want to search for DG in colB, then beginning with the next row search for the first occurrence of 123 in colA and then return 456 in colC.

I've tried various sumproduct formulae with no luck, i.e. =SUMPRODUCT(--(B5:B200="DG"),--(A5:A200=165),--C5:C200)

Here's my sample data:

colA----colB-----colC
---------DF
106--------------229
123--------------444
---------DG
117--------------678
123--------------456
152--------------100
286--------------750
123--------------111
---------KL
123--------------677


Thanks,
roothog