We started using ASANA recently and one of the ways to enter tasks quickly was via forms.
The tool that we used to create these forms was JOTFORM. When you create the form you have the option to add a number field that would increment when you apply the form.
For example in our case we have MR-14, MR16, etc.
So every time someone applies that form a new number is generated.
However, since this is populating fields (which by the looks of it are not searchable, please correct me if I am wrong…) it may not be of use to you unless you link the form field to populate your body text which is searchable. Just an idea…
Hope it helps.