Got it!

=SUMPRODUCT(--(VALUE(RIGHT(PosDeptNum,2))=$A7),--(PosStart<=G$6)*--(PosEnd=H$6)*PosHrs/40+
--(PosEnd=G$6)*--(PosEnd<H$6)*PosHrs/40*(PosEnd-G$6)/(H$6-G$6-1)+--(PosStartG$6)*--(PosStart<H$6)*PosHrs/40*
(H$6-PosStart)/(H$6-G$6-1))