Keyboard assignments for styles on Word for Win and Word for Mac

I regularly use Word for Windows and am trying to share a template with a friend who uses Word for Mac. The template works fine on both machines but I am having difficulties assigning shortcut keys to styles. Or more precisely, I seem to be unable to use the same key combinations on my friend's Mac as I do on my PC.

On Word for Windows I use a combination of the control key plus the letter 's', followed by a second character. For example:

Ctrl+s,1

Ctrl+s,Shift+1

My problem is that the Mac version of Word either does not accept a shortcut key with a shifted second character (for example, Ctrl+s plus the shifted numbers 2-9), or it accepts the assignment (Ctrl+s,Shift+1) but does not apply the style.  

I have almost no experience with the Mac and I suspect this is where the problem lies. I am hoping that someone could suggest keyboard combinations that make sense from a Mac point of view. Maybe I should be using something other than control with the first character, or other than shift for the second character. For example:

command+s,shift+1 or

Ctrl+s,Ctrl+1

Any guidance you could provide would be greatly appreciated.

Thanks,

Trip