The CAD Geek has a post about how to use commas in a sheet set sheet title:
The secret is to press and hold the ALT key while you type 0130. It will then insert a character that looks like a comma, but more importantly works with SSM.
Also, the comments had this useful tip:
You also can use %%44 in the sheet name, this will regenate a comma, in most .shx fonts, when translated into autocad.

