Thank you MrShorty!
Let's see if I can explain the thing.
I have a lot of technical drawings, beginning from the 80's until now, that have a numeral system this:
1 - If the object is simple, let's call it an "element", is made from one drawing, like drawing number (20).
2 - If the object is made from several "elements", it as a final drawing showing how the elements have to be combined (20), and a list of all the elements. Each one of the elements have a drawing of themselves (20-1), (20-2), etc...
3 - If one or more of that small pieces that make the big one are a little more complex, they to have a list of smaller pieces, like (20-1.1) (20.1.2), etc....

If I have a column with all the different drawing numbers I cannot order them as I want.
This is the order that I get when Ordering Ascendant:
12
113
145
150
145-1
145-1.2
150-1
150-1.2

This is what I would expect:
12
113
145
145-1
145-1.2
150
150-1
150-1.2

Does that make sense to you?

Thank you again!