I'm not the most knowledgeable person regarding macros and have found little help regarding what I want for a macro.
In instances due to lag or what ever reasons I haven't been able to get a heal off on a target before they're dead while I've casted Nature's Swiftness. Majority of the time I cast it in order to then give them an instant Healing Touch but they more often than not die in the time it takes me to hit that button. Then my Nature's Swiftness is wasted and I would have rather Rebirthed them at that point.
If there are no TBC Macro's there, I'd recommend looking up the perfect rotation for your spec and create your own using the repetative and easy to learn code "/cast *SPELL NAME*"
Although I'd recommend not using a Macro on WoW, I think it takes the fun out of combat, I especially would recommend not using a Macro for a healer, I think a healers job might be a tad too complicated for a Macro.