The ability you describe was added to VB
.NET, but not VB6 and before.
As Gonzalo said, you can define a range of beginning letters to be implicitly of a certain type, but it makes your code hard to read. There is no indication at the point of the variables declaration what type it is.
It seems really useful at first, but 2 months after you do it, you'l' be asking yourself, "What is this
Don't be tempted by the dark side. . .