Difference between ways of selecting the last row

Hello Forumnists,

As I am surfing this forum I noticed quite a few ways of selecting a simple range of data which could be changing from time to time, a dynamic range of sorts.

For example I wish to select a single column of data starting at A2.
Since the top boundary is known to us, what we need to do is go to the last possible row and then up till we meet a row with some data. I would define some sort of a variable like this:

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and then use it my selection like this:

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It works just fine but I really don't like the "[A1048576]" of it. Not all versions of excel have this particular number of rows. So I tried to define my variable like this:

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But it doesn't work. The question is why? I would really appreciate your help with this

Change the and for an &

Gosh, I'm such a newb...

Thanks a lot