Problem witch implementing big automaton

I'm not exacly understand how to use counter. Especially in process witch is responsible on changeing states. In last version I used something like this:

process (clk, rst)

begin

if (rst = '1') then

state_reg <= s0;

elsif rising_edge(clk) then

if divideclk = '1' then

state_reg <= state_next;

divideclk <= '0';

else

divideclk <= '1';

end if;

end if;

end process;

and in main process sensitivity list I had state_reg and stream. I'm not sure how to change it to use counter instead of state_reg and state_next?

Thanks in advance