Al,
Excel treats cells with numbers and letters differently than those with pure numbers. They have a workaround outlined here
https://support.microsoft.com/en-us/kb/214282Here is the issue and how I handle it....

Screen1 shows random Scott numbers in column A. Note that the numeric cells are shown as right justified and alphanumeric as left justified.
Screen2 shows how Excel sorts them, not what we want.
Screen3 show the addition of a new column named 'Sort'. In cell B1 type =REPT("0",4-LEN(-LOOKUP(1,-LEFT(A1,ROW($1:$10)))))&A1 and then copy this down into other cells in column B.
Screen4 shows after I have sorted on Column B, Scott number in column A are now how we want them.
Don