print to a non default printer

I am making an asp.net where users supposed to print tags after doing their works. the tags are crystal reports based. I added all the printers in the server (shared printers from some users computers) and i have a method return the nearest available printer to the user. the probleme is unless the printer is set as default printer to the server i have a "no printer are installed" exeption or the tags are printer in the default printer. here is my code:

string printername = getPrinter();
        ReportDocument rd =newReportDocument();
        rd.PrintOptions.PrinterName= printername;
        rd.Load(Server.MapPath("../GFile/TAG.rpt"));
        rd.PrintOptions.PrinterName= printername;
        rd.SetDataSource(sd);
        int number =int.Parse(tbxNumTaG.Text);
        try
        {
            rd.PrintToPrinter(number,false,0,0);
        }
        catch(Exception ex)
        {
            Page.ClientScript.RegisterStartupScript(GetType(),"printer Problems","alert('"+ ex.Message+" "+ printername +"Your associated printer not working contact the admin!');",true);
        }