How to implement a shift and decimal point on a time multiplexer

I am a student and I recently learned how to create VHDL code for 
displaying 4 digit time multiplexer on a coolrunner board. I am trying 
to expand my knowledge and learn how to make the digits slide(left or 
right) like they would on a billboard so when a digit slides left, it 
would slide into the rightmost display. I am also trying to use the 
decimal point on the display and how to make the system recognize where 
the decimal point should be during sliding.

here is a sample of my shifter code:

entity ShifterSample is
    Port ( clk : in  std_logic;
           reset : in  std_logic;
           data_i : in  std_logic_vector (31 downto 0);
           data_o : out  std_logic_vector (31 downto 0));
end ShifterSample ;

architecture Behavioral of ShifterSample  is
signal dataout_sig : std_logic_vector (31 downto 0);
begin

process (clk, reset, data_i, dataout_sig)
  begin
  if (reset = '1') then
    dataout_sig <= "00010010001101000101011001111000";
    --elsif (load ='1') then
  dataout_sig<=data_i;

  elsif (clk'event and clk = '1') then
    dataout_sig <= dataout_sig(27 downto 0) & dataout_sig(31 downto 28);
    end if ;
    end process;

data_o<=dataout_sig;
data_o<=data_o(27 downto 0) & data_o(31 downto 28);
end Behavioral;
--

Also how would I link this in my main file:

------------------------------

entity time_multiplexer_main is
  Port(clk : in std_logic;
       reset : in std_logic;
     data_in : in std_logic_vector(7 downto 0);
       seg : out std_logic_vector(6 downto 0);
       anode : inout std_logic_vector(3 downto 0));
end time_multiplexer_main;

architecture Behavioral of time_multiplexer_main is
component frequency_divider

  port( clk: in std_logic;
      reset: in std_logic;
      clock1: inout std_logic);
end component;

component time_multiplexer_4digit
port(clk : in std_logic; --multiplexing clock(1 kHz)
       reset : in std_logic; -- reset signal
     display_value : in std_logic_vector(15 downto 0); --BCD digits to 
be displayed
       seg : out std_logic_vector(6 downto 0); --7 cathodes
       anode : inout std_logic_vector(3 downto 0));
end component;




signal clk_1kHz: std_logic;-- this is a signal connecting the frequency 
divider to the time multiplexer
--signal dataout_sig:




begin

cop1: frequency_divider
    port map( clk=>clk,
      reset=>reset,
       clock1=>clk_1kHz);

cop3: time_multiplexer_4digit
  port map( clk=>clk_1kHz,
        reset=>reset,
        DISPLAY_VALUE=>"0001001000110100",-- DISPLAY value signal
        seg=>seg,
        anode=>anode);


end Behavioral;