Use this to do it manually: http://www.asciitable.com/

Or cut and paste to here to have it done for you: [Link: centricle.com]

Note you don't need to translate the "02h" and "03h" in the example you gave, the "h" suffix means those are already in hex.

So the translation of your example string would be:

02,20,2a,20,2a,20,52,4d,43,20,53,30,35,20,03

Note the commas were put in by me to separate the characters and make it readable. (As are the "%" symbols you will see in the centricle results.) Leave them out to get a truly raw string, if that is what the Nevo gear wants. Also, I am assuming that the spaces in your original example are significant. If they're not, you can leave all the "20"'s out of the translated string.

Hope that helps.