seperate string

this is how you would do it....

            string RxString = serialPort1.ReadExisting();
            string[] firstSplitString = RxString.Split(new char[] {',' });

            string[] secondSplitString;

            for (int i = 0; i < firstSplitString.Length; i++)
            {
                if (i == 0)
                {
                    secondSplitString = firstSplitString[i].Split(new char[] {'#' });
                    textBox3.Text = string.Format("{0} time {1}", secondSplitString[0], secondSplitString[1]);
                }
                else if (i == 1)
                {
                    secondSplitString = firstSplitString[i].Split(new char[] { '#' });
                    textBox4.Text = string.Format("{0} time {1}", secondSplitString[0], secondSplitString[1]);
                }
                else if (i == 2)
                {
                    secondSplitString = firstSplitString[i].Split(new char[] { '#' });
                    textBox5.Text = string.Format("{0} time {1}", secondSplitString[0], secondSplitString[1]);
                }
                else if (i == 3)
                {
                    secondSplitString = firstSplitString[i].Split(new char[] { '#' });
                    textBox6.Text = string.Format("{0} time {1}", secondSplitString[0], secondSplitString[1]);
                }
            }

first, you split on the comma to get the different "POOLS".  next you split each "POOL" on the # sign to get the text.

Yes you can do this.
In c# here is string.
string have method split in which you will provide the split character and this you return array of string.
string str;
str=Pool1#1234#abc#XYZ;
string arraystring[];
arraystring[]= str.split('#' ,str)