Question: Using vectors with the summation notation

I copied a column of figures from Excel and pasted them into an Maple worksheet.  Maple displayed a column vector with the appropriate values.  I set the variable y equal to this vector and was able to verify that, for example, y[3] had the correct value.  However, when I tried to use y[i] after a summation symbol which used i as the index I got the error message "Error, bad index into vector".  The summation expression worked fine when I redefined y by the following:

y:=  4,5,5,6,7,8,12,14

So, evidently the expression y[i] works fine in a summation when y is defined above but not when y is defined as a column vector with these values.  But if I am not using the summation symbol I can define y by setting it equal to the column vector and then do this

i:= 3

y[i]

and I get the output 5 as expected.

Can someone tell me how I might input a column of numbers from Excel and then access them with an index which is used by the summation symbol?

Second question:  It has been some years since I have been on this board and I have forgotten how to upload docs and how to incorporate Maple output into a post.  I would appreciate if someone could point me in the the right direction.

Thanks in advance