Hi,
No, you can't really do it like that.
You can't create an alias to individal pins "spanning" several ports like that - not that I know anyway.

And, another point:
When you say LED.1 = PortB.3 you assign the value of PortB.3 to LED.1 - that's definitely not what you want to do. To create aliases you use the VAR statement, just like you do when creating variables.
Code:
LED VAR PortB       ' LED is now an alias of PortB
Pretty useless example but anyway....

/Henrik.