Thanks Bixby. That was the page I was looking for!

I am disappoint. I thought I could maybe use macro names in place of action names. For instance..

Code:
mBio
/macroicon "Bio"
/ac "Bio" <tt>
/ac "Bio" <t>
/crosshotbar set "mBio2" LDR

mBio2
/macroicon "Bio II"
/ac "Bio II" <tt>
/ac "Bio II" <t>
/crosshotbar set "mBio" LDR
(I'd work Miasma into that as well) but alas, it does not work. The syntax is right, because standard actions will work)

I'll have to try an alternative using the methods Gardes brought up.