Message Numbering on Sequence Diagram

[MikeOL]

On a Sequence Diagram how can you format the Message sequence number to be an integer (1, 2, 3, …) rather then the default decimal (1.1, 1.2, 1.3, …)?

[Sunshine]

In sequence expression for the message tick start new group

[Mauricio Moya (Arquesoft)]

In other words: this is the standard for numbering a sequence

[wholley]

I have not found a way to change the default sequence diagram message numbering.  It would be useful to be able to easily change this.  Most other tools seem to make this feature simple to apply.