Get section by give index from PE header

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ASM

Hello guys,
I have problem, I want to add new section to PE section header automatically.

AddNewSection	PROC	szName:DWORD, dwSize:DWORD, Buffer:DWORD
	LOCAL	i:DWORD
	LOCAL	dwTarNum:DWORD
	LOCAL	dwAlignTo:DWORD
	LOCAL	roffset:DWORD
	LOCAL	rsize:DWORD
	LOCAL	voffset:DWORD
	LOCAL	vsize:DWORD

	MOV	ESI, Buffer

	MOVZX   EDX, [ESI].IMAGE_NT_HEADERS.FileHeader.NumberOfSections
	MOV     i, EDX
    
	MOV	EDX, [ESI].IMAGE_NT_HEADERS.OptionalHeader.FileAlignment
	MOV	dwAlignTo, EDX
	PUSH    dwAlignTo
	MOV	EDX, dwSize
	MOV	dwTarNum, EDX
	PUSH    dwTarNum
	CALL    PEAlign
	
	MOV     rsize, EAX

        MOV	EDX, [ESI].IMAGE_NT_HEADERS.OptionalHeader.SectionAlignment
	MOV		dwAlignTo, EDX
	PUSH    dwAlignTo
	PUSH    rsize
	CALL    PEAlign
	
	MOV     vsize, EAX
    
	MOV	EDX, [ESI].IMAGE_SECTION_HEADER[i-1].PointerToRawData + [EAX].IMAGE_SECTION_HEADE[i-1].SizeOfRawData
	PUSH    EDX
	MOV	EDX, [ESI].IMAGE_NT_HEADERS.OptionalHeader.FileAlignment
	MOV	dwAlignTo, EDX
	PUSH	dwAlignTo
	CALL    PEAlign
	
	MOV     roffset, EAX
    
	MOV	EDX, [ESI].IMAGE_SECTION_HEADER[i-1].VirtualAddress+[EAX].IMAGE_SECTION_HEADER[i-1].Misc.VirtualSize
	MOV		voffset, EDX
	PUSH	voffset
	MOV	EDX, [ESI].IMAGE_NT_HEADERS.OptionalHeader.SectionAlignment
	MOV	dwAlignTo, EDX
	PUSH	dwAlignTo
	CALL    PEAlign
	
	MOV     voffset, EAX
    
	PUSH    28h
	PUSH    0
	LEA	ECX, [ESI].IMAGE_SECTION_HEADER[i]
	PUSH	ECX
	CALL	memset

	MOV	EDX, roffset
	MOV	[ESI].IMAGE_SECTION_HEADER[i].PointerToRawData, EAX
    
	MOV	EDX, voffset
	MOV	[ESI].IMAGE_SECTION_HEADER[i].VirtualAddress, EDX
    
	MOV	EDX, rsize
	MOV	[ESI].IMAGE_SECTION_HEADER[i].SizeOfRawData, EDX
    
	MOV	EDX, vsize
	MOV	[ESI].IMAGE_SECTION_HEADER[i].Misc.VirtualSize, EDX
    
	MOV	[ESI].IMAGE_SECTION_HEADER[i].Characteristics, 0C0000040h
    
	PUSH	szName
	CALL	strlen
	PUSH	EAX
	PUSH	szName
	LEA	EDX, [ESI].IMAGE_SECTION_HEADER[i].Name1
	PUSH	EDX
	CALL    memcpy
    
	PUSH	rsize  
	PUSH    40h
	CALL    GlobalAlloc
	MOV	[ESI].IMAGE_SECTION_HEADER[i], EAX
    
	INC	[ESI].IMAGE_NT_HEADERS.FileHeader.NumberOfSections
    
	LEA	EAX, [ESI].IMAGE_SECTION_HEADER[i]
RET
AddNewSection ENDP

when I compiled theses errors showed up:

Error   8   error A2006: undefined symbol : Characteristics N:\My projects\Mal\msgVirus\msgVirus\main.asm   436 1   msgVirus
Error   12  error A2006: undefined symbol : GlobalAlloc N:\My projects\Mal\msgVirus\msgVirus\main.asm   448 1   msgVirus
Error   11  error A2006: undefined symbol : memcpy  N:\My projects\Mal\msgVirus\msgVirus\main.asm   444 1   msgVirus
Error   3   error A2006: undefined symbol : memset  N:\My projects\Mal\msgVirus\msgVirus\main.asm   422 1   msgVirus
Error   7   error A2006: undefined symbol : Misc    N:\My projects\Mal\msgVirus\msgVirus\main.asm   434 1   msgVirus
Error   10  error A2006: undefined symbol : Name1   N:\My projects\Mal\msgVirus\msgVirus\main.asm   442 1   msgVirus
Error   1   error A2006: undefined symbol : PointerToRawData    N:\My projects\Mal\msgVirus\msgVirus\main.asm   399 1   msgVirus
Error   4   error A2006: undefined symbol : PointerToRawData    N:\My projects\Mal\msgVirus\msgVirus\main.asm   425 1   msgVirus
Error   6   error A2006: undefined symbol : SizeOfRawData   N:\My projects\Mal\msgVirus\msgVirus\main.asm   431 1   msgVirus
Error   9   error A2006: undefined symbol : strlen  N:\My projects\Mal\msgVirus\msgVirus\main.asm   439 1   msgVirus
Error   2   error A2006: undefined symbol : VirtualAddress  N:\My projects\Mal\msgVirus\msgVirus\main.asm   408 1   msgVirus
Error   5   error A2006: undefined symbol : VirtualAddress  N:\My projects\Mal\msgVirus\msgVirus\main.asm   428 1   msgVirus

I made my search and I found that IMAGE_SECTION_HEADER don't accept indexing "[i]".
So, how to get section by giving index from PE header? OR how to retrieve sections from PE header?