http://deafandblind.com/word_frequency.htm
If your saying that the order has been preserved, and that it is simply a substitution encryption, you can write a program that counts the frequency of each symbol. The most frequent symbol is designated as one letter, the next most frequent is designated as another letter, and so on and so forth. Once the program gives you the tentative answer it should be legible. You can fine tune the substitution from there if it isn't already correct.