Set nice value in an executable in a script?

Is it possible to set a nice value for an executable in a script so that every time the executable runs it has this nice value?

I'm trying to set aerender (After Effects terminal renderer) to run at +18 by replacing the original aerender script with a bash script with something like this in it:

nice -n +18 '/Applications/Adobe After Effects CS6/Nice_aerender'

and renaming the original script to Nice_aerender.

Instead of creating a script, you can define an alias to invoke your script/executable with nice value of your choice.

An alias is preferable for two reasons:

1) You don't need to modify global filesystem values, only your personal preference data.
2) This restricts it to when it's run interactively.

I don't see how I can set nice value of an alias. Can I see an example of how that would work?

---------- Post updated at 03:18 PM ---------- Previous update was at 01:21 PM ----------

Never mind, I now realize you meant alias, as in unix alias, not Finder alias. That's a good idea but won't work because the script that's calling the executable is controlled by me. It reads the executable directly and executes it from a path in it's script.
What I'm trying to do is tell our render farm not to put my machine into a coma.