Using XL2003 on Win2000

I'm setting up a workbook for other folks to use; they may edit the number
of elements in several arrays (which I've hardcoded at the top of the module
so they can find them):

MyArrayOfStudentNames =Array("Name1", "Name2", "Name3")
MyArrayOfStudentGradeLevel =Array("7", "3", "12")

Here's my first problem; I want to allow them to declare/fill a
one-dimensional array of _numbers_. I /could/ have them put each number in
quotes, then pull the value out in code- but that wastes processing power.
Is there any way to declare a one-dimensional array by populating it with
numbers? The following _doesn't_ work because it appears to create a
multidimensional array with three dimensions of (0 to 7, 0 to 3, and 0 to
12):

MyArrayOfStudentGradeLevel =Array(7, 3, 12)

Then my second problem comes into play;

Since I don't know how many items will be in the one-dimensional array (once
I learn how to dimension it), my code needs to use each value then stop
after the last one without erroring. I was going to use a loop:

For each StudentGradeLevel = 1 to 10
'do stuff
Next

but in the above example, only 3 items exist, so the array is actually
dimensioned as a (1 to 3) or (0 to 2) array; my loop will error out because
my array isn't that large. To code defensively, how do I determine how many
items are in the array first, so I can make that the maximum of my loop?
Items may not be sequential, so what I really need is the maximum array
value regardless of whether it is filled (e.g. could be Array(3,5, ,12,6, )
and should return that there are 6 items to be looped through)

Thanks bunches and bunches in advance,
Keith

--
The enclosed questions or comments are entirely mine and don't represent the
thoughts, views, or policy of my employer. Any errors or omissions are my
own.