Function returning the number of active symbol on the account.

string OrderSymbolArray[];  //Globally Declared
//+------------------------------------------------------------------+
int CountOrderSymbols()
 {
 int as=0;
 ArrayResize(OrderSymbolArray,0);
 for(int x=OrdersTotal()-1;x>=0;x--)
    {
    bool found=false;
    if(OrderSelect(x,SELECT_BY_POS) && (OrderType()==OP_BUY || OrderType()==OP_SELL))  //Check excluding Pending Orders
    //if(OrderSelect(x,SELECT_BY_POS))                                                 //Check Active & Pending Orders
       {
       for(int y=as-1;y>=0;y--)
          {
          if(OrderSymbol()==SymbolArray[y])
             {
             found=true;
             break;
             }
          }
       if(!found)
          {
          as++;
          ArrayResize(OrderSymbolArray,as);
          OrderSymbolArray[as-1]=OrderSymbol();
          }
       }
    }
    return(as);
 }
 

This will count the symbols and also put the symbol names in an array.

It's old code of mine, but I thinjk that it should work ok