Regex query not using index

I'm running a simple query on 8.2. With this syntax, Explain indicate
that the index is scanned:
select * from eod where name = 'AA'

However, when I change the query to use simple regex:
select * from eod where name ~ 'AA'

now Explain indicates a seq scan:
Index Scan using equity_eod_symbol_idx on equity_eod (cost=0.00..8.27
rows=1 width=149)
Index Cond: ((symbol)::text = 'AA'::text)

Is there any way to 'encourage' Postgres to hit the index when using
regex? Do I need to create a functional index or something?
Without the index in play, I really can't use regex on any of my larger tables.