by Marcus Green.
In that case I have good news for you. The latest version will allow you to do this. You can find it in Github at
(it is also in the waiting list for approval in the Moodle pluginsdatabase).
You can see the docs describing the change at
Instead of a dropdown you enter your criteria into a standard text box and it is checked on save to make sure that it is P, M or D followed by anything that is a number, i.e. your requested P15.
I spoke to some people at the Edinburgh Moodlemoot (a wonderful event) and they emphasised the need for an arbitrary number of levels. I intend to update the docs further to emphasise this feature/change.