if you have numbers of varying numbers of digits, you could make a custom excel formula to go through each character of a string until IsNumber = true. Keep track of the characters passed and do a substring to pull that part of the string out. Use that formula (or do a macro) to create another column on numbers with the end letter removed and sort the original column according to this one
also, if there are only a few different non-numeric characters, you can make columns of
Search(string, 'a') Search(string, 'b')
Each column will return the location of the non-numeric character in the number. Then make a column of the smallest of these locations that's not zero
min(if(search > 0, a column, 9999), if(search>0, b column, 9999))
with that, you can use a function like Left(string, min location), or something like Left im not sure off the top of my head, but it'll pull out the number hopefully :P. I can do it for ya on a google spreadsheet if you'd like