From http://forum.cheatengine.org/viewtopic.php?t=533598&postdays=0&postorder=asc&start=15&sid=e8ca901927c9bb05a66f4715058386cb

PsApi.pas

PsAPI; //Add this to "uses" 

function GetModuleBaseAddress(ProcessID: Cardinal; MName: String): Pointer; 
var 
  Modules         : Array of HMODULE; 
  cbNeeded, i     : Cardinal; 
  ModuleInfo      : TModuleInfo; 
  ModuleName      : Array[0..MAX_PATH] of Char; 
  PHandle         : THandle; 
begin 
  Result := nil; 
  SetLength(Modules, 1024); 
  PHandle := OpenProcess(PROCESS_QUERY_INFORMATION + PROCESS_VM_READ, False, ProcessID); 
  if (PHandle <> 0) then 
  begin 
    EnumProcessModules(PHandle, @Modules[0], 1024 * SizeOf(HMODULE), cbNeeded); //Getting the enumeration of modules 
    SetLength(Modules, cbNeeded div SizeOf(HMODULE)); //Setting the number of modules 
    for i := 0 to Length(Modules) - 1 do //Start the bucle 
    begin 
      GetModuleBaseName(PHandle, Modules[i], ModuleName, SizeOf(ModuleName)); //Getting the name of module 
      if AnsiCompareText(MName, ModuleName) = 0 then //If the module name match with the name of module we are looking for... 
      begin 
        GetModuleInformation(PHandle, Modules[i], @ModuleInfo, SizeOf(ModuleInfo)); //Get the information of module 
        Result := ModuleInfo.lpBaseOfDll; //Return the information we want (The image base address) 
        CloseHandle(PHandle); 
        Exit; 
      end; 
    end; 
  end; 
end; 

procedure TForm1.Button1Click(Sender: TObject); 
var 
  WHandle : HWND; 
  PHandle: THandle; 
  Address, X, Buffer: DWORD; 
  NewValue: Cardinal; 
  ProcessID : Cardinal; 
begin 
  ProcessID := 0; 
  NewValue := $09; 
  WHandle := FindWindow(nil, 'test'); 
  GetWindowThreadProcessId(WHandle, @ProcessID); 
  Address := Integer(GetModuleBaseAddress(ProcessID, 'test.exe')) + Integer($0002E7AC); 
  PHandle := OpenProcess(PROCESS_ALL_ACCESS, False, ProcessID); 
  ReadProcessMemory(PHandle, Ptr(Address + $7C), Addr(Buffer), 4, X); 
  ReadProcessMemory(PHandle, Ptr(Buffer + $21C), Addr(Buffer), 4, X); 
  ReadProcessMemory(PHandle, Ptr(Buffer + $8), Addr(Buffer), 4, X); 
  WriteProcessMemory(PHandle, Ptr(Buffer), @NewValue, 1, X); 
  CloseHandle(PHandle); 
end;