I'll show you a little patching trick.
Code:
PUSH 0
CALL PARAM1
DB "Whatever",0
PARAM1:
CALL PARAM2
DB "Hello World",0
PARAM2:
PUSH 0
CALL MessageBoxA
Looks like jibberish to anyone who knows a little ASM but it's actually a pretty effective way of getting strings into fuction calls without having to mess with other sections.
The first 2 CALLs look totally out of place, but if you know what a CALL effectively does (PUSH the address of the next "instruction" and then JUMP to another part of code) then it's perfect for this deal. You're not likely to find that in an ASM book