Shield and barrier macro help, please

I use A LOT of mouseover macros on my Disc priest and one of them is this:

/cast [mod:shift] Rapture; [target=mouseover,help,nodead][]Power Word: Shield

While it works fine as is I would also like to add “Power Word: Barrier” to it so I can cast it by pressing another modifier button, but I can’t for the life of me figure out how to do it. I’ve looked on sites like WoWHead and other forum posts but I haven’t found anything that can help me. I’ve been trying for weeks now and I haven’t made any progress on my own so now I’ve come to ask you for help, please help me with my macro.

/cast [mod:shift] Rapture; [mod] Power Word: Bartier; [@mouseover,help,nodead] [] Power Word: Shield