Visual Studio 2012 How to find the existing connection string

I need to update a project and I am looking for the DB connection string.  It is not in an obvious place.  Here is how we call the DB.

String cs3 = "INSERT INTO tblWP_TS_Day VALUES(NEWID(),@sd,@st,@et,@lit,@lot,@nt,@ot,@sit,@hot,@vat,@tt,@euk,@ct,'');";
                        Cm.ex(Cm.plw, cs3, null, ch, null, null, null, null, null, null, false);

The 'plw' contains the connection string but I can't find where that is set.  I right clicked on it and went to 'Go To Definition' and it brought me to this.

namespace BaseClassLibrary
{
    public class Cm
    {
        public static string cp;
        public static string plc;
        public static string pld;
        public static string pldt;
        public static string plw;

        public Cm();

        public static string ex(string cmm, string fc, string cmt, Hashtable ch, string ot, Ob rob, ArrayList al, Ts gts, Dl gdl, Label rl, bool q);
    }
}

I am trying to find where these variables are set.  I've done a search on the whole project and nothing shows up.  I am thinking there is a 'behind the scenes' spot where it can be set in a project.  I've looked in the 'Properties' page and clicked through each link and can't find it.  

Any idea?

Thanks