This is fairly simple to achieve. Split the string at the comma, then remove the IP Address: Host: and Time: portions of the text, saving what's left into your text boxes.
One option to remove them is like this:
replace(VARIABLENAME, "IP Address: ", "")
Edit: Here is an example
Dim infoString As String = "IP Address: 10.21.4.1, Host: RTR-BIF01,Time: 18:00 GMT"
Dim split As String() = infoString.Split(","c)
txtip.Text = Replace(split(0).Trim(), "IP Address: ", "")
txthost.Text = Replace(split(1).Trim(), "Host: ", "")
txttime.Text = Replace(split(2).Trim(), "Time: ", "")