Simple Encryption Program in VB Console App using String functions - arrays

Question

I am just new to VB and I'm having trouble in doing this program since I got no idea how to access each letter in a word in just one input.
Say, I am ask to enter a string and I input "help" the output should be something like "$%&(".
My only idea with this is that each letter of the entered string should be read so that the symbols to be substituted on each letter could be determined (which is I dunno how). I only know how to, if the letters will be entered one by one and the index of the array is fixed OR the letters to be encrypted are already declared such as this:
Dim a() As String = {"h", "e", "l", "p"}
Dim b As String
Console.WriteLine("String:")
For Each b In a
Console.Write(b)
Next
Console.WriteLine()
Console.WriteLine()
Console.WriteLine("Encryption:")
For Each b In a
Select Case b
Case "A", "a"
Console.Write("!")
Case "B", "b"
Console.Write("+")
Case "C", "c"
Console.Write("#")
Case "D", "d"
Console.Write("$")
Case "E", "e"
Console.Write("%")
Case "F", "f"
Console.Write("'")
Case "G", "g"
Console.Write("(")
Case "H", "h"
Console.Write(")")
Case "I", "i"
Console.Write(",")
Case "J", "j"
Console.Write(".")
Case "K", "k"
Console.Write("~")
Case "L", "l"
Console.Write("}")
Case "M", "m"
Console.Write("|")
Case "N", "n"
Console.Write("[")
Case "O", "o"
Console.Write("\")
Case "P", "p"
Console.Write("]")
Case "Q", "q"
Console.Write("!")
Case "R", "r"
Console.Write("^")
Case "S", "s"
Console.Write("_")
Case "T", "t"
Console.Write(":")
Case "U", "u"
Console.Write(";")
Case "V", "v"
Console.Write("<")
Case "W", "w"
Console.Write("=")
Case "X", "x"
Console.Write(">")
Case "Y", "y"
Console.Write("?")
Case "Z", "z"
Console.Write("#")
End Select
Next
Console.ReadLine()
Your help will be greatly appreciated. Thanks in advance.

Answer 1

Dim a as String = "whatever your string is"
for i as integer = 1 to len(a)
Dim curLetter = Mid(a, i, 1) ' this will give you the current character.
' do your encrypting here.
Next
There are better ways to encrypt things, but for your purposes for now this should suffice.

Answer 2

Check this:
Imports System.Linq
Module StartupModule
Private _characterMaps As New Dictionary(Of Char, Char) From {
{"A"c, "!"c}, {"B"c, "+"c}, {"C"c, "#"c},
{"D"c, "$"c}, {"E"c, "%"c}, {"F"c, "'"c},
{"G"c, "("c}, {"H"c, "C"c}, {"I"c, ","c},
{"J"c, "."c}, {"K"c, "~"c}, {"L"c, "}"c},
{"M"c, "|"c}, {"N"c, "["c}, {"O"c, "\"c},
{"P"c, "]"c}, {"Q"c, "!"c}, {"R"c, "^"c},
{"S"c, "_"c}, {"T"c, ":"c}, {"U"c, ";"c},
{"V"c, "<"c}, {"W"c, "="c}, {"X"c, ">"c},
{"Y"c, "?"c}, {"Z"c, "#"c}
}
Sub Main()
Dim original As String = "Hello world!"
Dim characters = From c As Char In original.ToUpper
Select GetEncodedCharacter(c)
Console.WriteLine(New String(characters.ToArray))
Console.ReadLine()
End Sub
Private Function GetEncodedCharacter(value As Char) As Char
If _characterMaps.ContainsKey(value) Then
Return _characterMaps(value)
Else
Return value
End If
End Function
End Module