UNKNOWN_SIZE  = 0x9

struct UNKNOWN
  char      db ?
  szUnknown db UNKNOWN_SIZE dup (?)
ends
    

mov [lpUnknown],eax      ; eax is pointer to reallocated memory block from HeapReAlloc
mov ebx,eax
mov edx,[iUnknownCount]  ; number of allocated structs
dec edx                  ; set to current subscriptor
mov al,[char_current]    ; char_current is a db value
virtual at ebx
unknown UNKNOWN
end virtual
mov [unknown.char+edx],al        ; put char_current to char member
invoke lstrcpy,[unknown.szUnknown+edx],szBuffer ; szBuffer is a string from WM_GETTEXT message, how to copy to szUnknown member ?
    

 lea ecx,[unknown.szUnknown+edx]
 invoke lstrcpy,ecx,szBuffer