Concatenating with fixed widths despite number of integers in column A

I need to concatenate three columns into one long string at fixed widths. The problem I am having is that column A are numbers 1-500, so that when I use this formula =concatenate(Sheet1!A1," ",Sheet1!B1," ",Sheet1!C1), numbers 1-9 are one space off from 10-99, and then 100-500 are again one space over, making my next task very tedious--the next task being separating all the data using the fixed width function (I've been manually doing 1-9, 10-99, and 100-500 as separate chunks).

Column B is short text and column C is a long string of text at variable fixed widths. When I say variable fixed widths, I mean that some of the rows are at different fixed widths than the others.

As you see in the formula above I tried adding extra spaces after the numeral to account for the different number of integers to no avail. I also tried formatting the numbers as "special" so that 1 was 00001, etc, but lost all the formatting when I concatenated.

Thanks for any help!
Chloe

Perfect. Thank you!