Concatenating with Left padded Zeros in MS Excel

You can use the formatting options in the TEXT() function. The syntax is TEXT(value, format_text), so in your example you'd use a formula like: =TEXT(A1,"00000") To join the two numeric strings together =CONCATENATE("1027", TEXT(A1,"00000")) See: http://office.microsoft.com/en-us/excel-help/text-function-HP010062580.aspx

OR   The right function will do what you want, if you put a bunch of zeroes before your number. If you want 5 digits total, you'd do something like this: =right("00000" & 45, 5) This would output 00045. If you are putting another number before it, you can just keep concatenating, like this: =1027 & right("00000" & 45, 5) You can, of course, replace any of those values with cell references to make it all more dynamic.