Sort a group based on custom data.

In the web console, I am trying to sort a group based on information from a custom data rule. The custom data is a route number, and I have it set up to collect the data as an integer not a string. However, when I sort the group based on the route number column, it treats the number as text. For example it will sort the route numbers like this: 1, 11, 2, 21, 3, 31. What I would expect from sorting integers it to have it sort like this: 1, 2, 3, 11, 21, 31. Is there a way to have the group sorting act in this fashion? I am using MobiControl 13.4.0.4962. The devices each have an ini file with the route number information. A data collection rule takes that info and assigns it to the device in the web console.