include 'macros.txt' ;some part push to section cases
include 'data.txt'     ;some data push to section cases

section code
 ...
section data
 ...
section cases
 ...
    

;if comment include 'data.txt' section cases it will become empty.
include 'data.txt'     ;some data push to section cases

section code
 ...
section data
 ...
section cases          ;this section fill auto(not hands) from another places code
 rept x_dat { dd 0 }   ;this auto push from 'data.txt'
    

If you need it so much, then no one prevents you from allocating a section through VirtualAlloc and writing code that performs these actions (placing data in it from data.txt).

include 'macros.txt' ;some part push to section cases
include 'data.txt'     ;some data push to section cases

section code
 ...
section data
 ...
virtual at rbx ; section cases
 ...
end virtual    

;first describing virtual
virtual at ebx
 label1 dw ?
label2 dd ?
end virtual
;than using in code
mov ax,[label1] ;will be assembled mov ax,[ebx]

    

Not understood how i could from include 'macros.txt' or section code
push code in virtual at rbx ; in section cases ?

I know this:

Code:

;first describing virtual
virtual at ebx
 label1 dw ?
label2 dd ?
end virtual
;than using in code
mov ax,[label1] ;will be assembled mov ax,[ebx]

    

macro push_cases { push_cases_label: virtual at rbx } ; from macros.txt
include 'macros.txt' ;some part push to section cases
include 'data.txt'     ;some data push to section cases

; from data.txt
macro push_cases {
    push_cases
    cases0 dd 1000 dup (0) ; ...
}
; ---- end data.txt ----

section code

  lea rbx, [push_cases_label]
  mov eax, [cases0 + 15 * 4]
 ...
section data
 ...
; virtual at rbx ; section cases
 push_cases
end virtual    

section data
...
; virtual at rbx ; section cases
push_cases
end virtual