Numbering pages and subsections

I've read through a few threads and tried section numbers, but can't work this out.

Pg1 - cover Pg2 - contents Pg3 - section a cover Pg4 - section a 1 of 2 Pg5 - section a 2 of 2 Pg6 - section b cover Pg7 - section b 1 of 2 Pg8 - section b 2 of 2 Pg9 - cover

I'm trying to get "1 of 2" etc generated automatically based on starting a new section, independent of page numbers. Sections don't seem to do this, but I can't work out what will.

Any clues?