The combination of A+ and Network+, or A+ and Server+ count as an elective for MCSA, and earning the MCSA counts as one elective towards the MCSE. Thus, in a manner of speaking, the Network+ counts as about half an exam towards MCSE, but only if you earn the MCSA along the way to MCSE. You'd probably be better off pursuing Security+ which does count directly as an elective for MCSE, if you want to count a CompTIA exam toward your total accumulation. But indeed earning Network+ is probably a good idea anyway, especially if you want to develop or strengthen your networking background in preparation for taking the MCSE exams, nearly all of which include anywhere from some to substantial networking content.
HTH, and thanks for posting.
This was first published in September 2006