Visual basics help-Variables in for loop - vb.net

Question

I'm trying to get the integers of "num3"(input from the user) and squaring each character and eventually see if its a "happy number"=1 or a "unhappy number" includes 4
For example, 19 is happy number 1^2+9^2=82 , 8^2+2^2=68,6^2+8^2=100, 1^2+0+0=1
Sub Main()
Dim number, num2, total As Integer
Dim num3 As String
Console.Write("pick a number:")
number = Console.ReadLine()
num2 = 0
num3 = Convert.ToString(number)
Do Until total = 1 Or num2 = 4
For Each num3 In num3.Substring(0, num3.Length)
For counter = 1 To num3.Length And num3 = num3.Substring(0, num3.Length)
num2 = num3 ^ 2
total = total + num2
Console.WriteLine(total)
Next
num3 = total
Next
Loop
Console.ReadLine()
If total = 1 Then
Console.WriteLine("happy number")
ElseIf num2 = 4 Then
Console.WriteLine(number & "is a unhappy number")
Console.ReadLine()
End If
End Sub
End Module
however i'm stuck whether "num3" replace itself from the for loop

Answer 1

Here, I believe this should work:
Dim InputNum As Integer = 45 'Your input number
Dim TempNum As Integer = InputNum 'Here we hold number temporarily during steps 19>82....
Do
Dim SumTotal As Double = 0 'sum of numbers squares
For Each number As Char In TempNum.ToString
SumTotal += Integer.Parse(number) ^ 2
Next
TempNum = CInt(SumTotal)
Debug.Print(TempNum.ToString)
'If result is 4 it will loop forever
If SumTotal = 4 Then
Console.WriteLine(InputNum & " is an unhappy number")
Exit Do
ElseIf SumTotal = 1 Then
Console.WriteLine(InputNum & " is a happy number")
Exit Do
End If
Loop