There are a bunch of the newer macros added in beta phase 4 listed here: beta phase 4 patch notes

The /hotbar and /crosshotbar (abbreviated /chotbar) commands are the ones you're looking for.

I believe you'd want something like:

/ac "Cleric Stance" <me>
/chotbar change 7

and

/ac "Cleric Stance" <me>
/chotbar change 1