You should add this function Space : Return a string consisting of a specified number of spaces.
With the comment of @Lankymart you can write something like that in vbscript :
Option Explicit
Dim Title,Input,i,OutPut
Title = "Add a space after every character in VBS"
Input = InputBox("Hello There.",Title,"Hello There.")
If input <> "" Then
For i = 1 To Len(Input)
OutPut = OutPut & Mid(Input,i,1) & space(1)
Next
End If
MsgBox OutPut,vbInformation,Title
Inputbox "The String " & chr(34)& Input & chr(34) &" is converted to ",Title,OutPut