I dont know about visual basic.. but here is some c++ code 
It would be nice if somebody posted some code in vb cuz i would like to know how to do it also ;?
Code:
#include <windows.h>
#include <iostream>
using namespace std;
void WriteMem(char* window, LPCVOID address, int value)
{
cout<< "Run cheat/hack after running the game for the cheat to work properly." << endl;
cout<< "Code by VirusInfection." << endl;
HWND hWnd = FindWindow(0, window);
DWORD proc_id;
GetWindowThreadProcessId(hWnd, &proc_id);
HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, proc_id);
BYTE newdata[]={value};
DWORD newdatasize = sizeof(newdata);
WriteProcessMemory(hProcess, (LPVOID)address, &newdata, newdatasize, 0);
CloseHandle(hProcess);
}
void ReadMem(char *window, LPCVOID dAddr)
{
int tbuf;
HWND hWnd = FindWindow(0, window);
DWORD proc_id;
GetWindowThreadProcessId(hWnd, &proc_id);
HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, proc_id);
ReadProcessMemory(hProcess, dAddr, &tbuf, 4, NULL);
cout<<tbuf;
}
int main()
{
WriteMem("Engine",(LPCVOID)0x55D6A98, value here);
ReadMem("Engine", (LPCVOID)0x55D6A98);
system("PAUSE>NULL");
}
Note: This code is part of my private ca hack. The values have been changed but the addresses remain, so the user can put their "preferd" value in.
Enjoy!