Not sure how to go about this (or even where to start).

I need to produce a list of all accounts who have kept their balance above 100 for the last 2 years.

Problem is, I only have 2 tables, current balance and transactions and no balance history, ie....

table a (1-1)
accNum , balance

table b (1-n)
accnum, transDate, (+/-)transVal

Somehow I need to work the balance back in time, checking after applying
each transaction in reverse that the value stays above 100.

Can someone point me in the right direction ?

I can do this no problem in VB but it doesn't feel particularly elegant and I'm
sure it must be possible to perform a calculation like this in Access or SQL.

Thanks Garry