Hooking mid-function to change value?

#include <windows.h>
#include <iostream>

DWORD dwJmpBack = ((DWORD)GetModuleHandleA("Test.dll")+0x424E2), cmdOld_ = 0;

typedef struct
{
	int ServerTime; //0x0000 
	int CurrentButton; //0x0004 
	int ViewAngles[3]; //0x0008
	char _0x0014[24];
}usercmd_t;//Size=0x002C

typedef struct
{
	usercmd_t usercmds[128];
	int currentCmdNum; // 0x16E8

	usercmd_t *GetUserCmd(int cmdNum)
	{
		int id = cmdNum & 0x7F;
		return &usercmds[id];
	}
}input_t;

__declspec(naked) void MyHook()
{
	__asm
	{
		PUSHAD;
		PUSHFD;
	}
        input_t * Input_T = ( input_t* )0x010638A4;
	usercmd_t* cmdOld = Input_T->GetUserCmd( Input_T->currentCmdNum - 1 );
	usercmd_t* cmd = Input_T->GetUserCmd( Input_T->currentCmdNum );
	cmdOld->ServerTime = cmd->ServerTime + 1;
	cmdOld_ = Input_T->currentCmdNum - 1;
	__asm
	{
		POPAD;
		POPFD;
		mov ecx, cmdOld_;
		push ecx;
		jmp [dwJmpBack];
	}
}

void MakeJMP(BYTE *pAddress, DWORD dwJumpTo, DWORD dwLen)
{
	DWORD dwOldProtect, dwBkup, dwRelAddr;
	VirtualProtect(pAddress, dwLen, PAGE_EXECUTE_READWRITE, &dwOldProtect);
	dwRelAddr = (DWORD) (dwJumpTo - (DWORD) pAddress) - 5;
	*pAddress = 0xE9;
	*((DWORD *)(pAddress + 0x1)) = dwRelAddr;
	for(DWORD x = 0x5; x < dwLen; x++) *(pAddress + x) = 0x90;
	VirtualProtect(pAddress, dwLen, dwOldProtect, &dwBkup);
	return;
}

BOOL APIENTRY DllMain(HANDLE hDllHandle, DWORD dwReason, LPVOID lpreserved)
{
	if(dwReason==DLL_PROCESS_ATTACH)
	{
		MakeJMP((BYTE*)((DWORD)GetModuleHandleA("Test__.dll") + 0x424DB), (DWORD)MyHook, 0x6);
	}
	return TRUE;
}

MOV ECX,[EAX+1600h] //Value of the current cmd
PUSH ECX