Use a different font or use tabs, at least it will adapt a little bit the differences.
You can always try to get the measurement of the strings given the used font and then add spaces accordingly.
A sample of what I mean can be found
here[
^] in C#.
Here[
^] in VB.
I guess this will be a good starting point for you.
PS: I've used google with this search string:
get width of string using non fixed font
Good luck!