in over my head ascii

[nephish at xit.net]

Hello there,
i need to write a script that can transfer info back and forth with a
data server at so-and-so ip.

i have Programming Python, which covers socket programming. So thats
cool. But what i need to know how to do is make a message in ascii that
is what the server is looking for.

for example , to send a request, the first three bytes have to be ascii
"STX"
then there has to be  4 bytes that show the length of the message
then the actual message
then the last three bytes have to be "ENX"

also all int variables must me unsigned long-int (32 bit).

so here is what i need to know,
1 how do i make something in ascii bytes to send off to this server ?
2 how can i make sure something is a 32bit unsigned long int. ?

If the answers i am looking for are pretty straightforward, please let
me know., If they are long and complicated, please point me to some
good documentation . 

thanks for all,
sk