FindWindowW() retiurning 0 when used within Indicator code

[Osazee Asikhemhen]

Hello Friends

Please help me look into this code. It works well inside EA to addach custom indicator to chart.

But when used as an indicator, it doesn't work. It Opens the indicator Dialogue, but doesn't click "OK" to add the indicator to chart.

The code is MQL4

Thanks

#import "user32.dll"
   int  RegisterWindowMessageW(string MessageName);
   int  PostMessageW(int hwnd,int msg,int wparam,uchar &Name[]);
   int  FindWindowW(string lpszClass,string lpszWindow);
#import

#define VK_RETURN 13 //ENTER key


//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+  
void StartCustomIndicator(int hWnd,string IndicatorName,bool AutomaticallyAcceptDefaults=false)
{
   Sleep(200);
   uchar name2[];
   StringToCharArray(IndicatorName,name2);
   int MessageNumber=RegisterWindowMessageW("MetaTrader4_Internal_Message");
   int r=PostMessageW(hWnd,MessageNumber,15,name2);
   Sleep(200);
   if(AutomaticallyAcceptDefaults) {
      Print("Custom Indicator - "+IndicatorName);
      int ind_settings = FindWindowW(NULL, "Custom Indicator - "+IndicatorName);
      
      PostMessageW(ind_settings,0x100,VK_RETURN,name2);
     
   }
}
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void AddIndicator(string indicator_name)
{
 int hWnd = WindowHandle(Symbol(), 0);
 StartCustomIndicator(hWnd, indicator_name, true);
}