tGFXAccess *pGFXAccess = 0x0f0422d; // sample address
LPVOID ptr1 = pGFXAccess;

__asm
{
    // Save registers
    pushad

    // Restore these from after the dllobj was created
    mov eax, dwEax_setup
    mov ebx, dwEbx_setup
    mov ecx, dwEcx_setup
    mov edx, dwEdx_setup

    // Params to open the archive file for access
    push lpVar1
    push paccess
    push pfilename

    // Code to open the archive file for access
    mov ecx, ptr1
    mov edx, [ecx]
    mov eax, [edx + 0x10] // how do we calculate the place of function? LOL
    call eax

    // Store the result
    mov dwResult, eax

    // Restore registers
    popad
}