This is a simple targeting system that allows you to set one target which is aliased to a period. You could adapt it (and perhaps I will) for multiple targets. Note if you go that route that there is no need to make multiple alias like t1, t2, etc. when regular expressions can consolidate all of them into one alias. So for the one target system:

Alias name:

t *

Alias text (Send to Script):

SetVariable("target", "%1")
Note ("Target set to %1.")

That lets you set your target variable. Now add alias name:

t

Alias text (Send to Script, Expand Variables):

Note("Current target is @target.")

Now, typing "t" by itself will tell you your target variable's contents. Finally, for the fun part, add alias name:

*.

That's star dot. Give it the text (Send to Script, Expand Variables):

Execute ("%1 @target")

What this will do is let you type ANY command and simply end it with a period to have it insert your target's name. You might want to choose another non-alpha character if you tend to end your sentences in say/tell with periods (I don't). Also note that when you make other aliases it is often best to Send to "Execute" rather than "World" so that the period is evaluated!