Addition of substeps in job

Hi Experts,

We have a job in which it has 15 steps, and was executing fine till last year and thereafter it was disabled, now customer wants to modify it, by which I mean at step 13 he is asking us to add sub steps say for example: 13.1, 13.2 etc and so on upto 13.9 sub steps, My question is that CAN WE ADD SUB STEPS to a step ,if so how can we achieve that? and continue after 13.9 to 14 step.

 And also would like to know if we have any better idea or process to simplify our this process. It will be great if we can use something from system to achieve the same.

My SQL server is 2008 R2.

Thanks in advance.