Applying a macro to text chat

Is there some way to apply a macro to any given text that you put into the chatbox?  For example, if I wrote: #oneliner "Never should have come here" The result would be something like: Ahnuld raises his axe and says in a whiny voice "Never should have come here" before swinging it down for 5 damage. What my personal end goal would be is a macro #OOC I can enter that applies a highlight or some kind of text effect to more easily distinguish between a player talking in and out of character.

You could use a query. The code for #one-liner would be: Ahnuld raises his axe and says in a whiny voice "?{One-liner|Never should have come here}" before swinging it down for 5 damage. When you run the macro, it will prompt you for the quip and insert it accordingly, but default to "Never should have come here".

Hm, it works but I'm not a big fan of making a one-step process into two steps, particularly if one of those steps involves a teeny tiny text box to type in.  Is there no way to directly reference the text box itself in the macro?

This would be in essence passing a variable to a macro, and is not strictly possible. You could use a rollable table (which would incidentally give you highlighting of the variable result), but no control over what is said. The two step process actually results in only one extra key press (a return) to trigger; you still type the macro name and the quip. As for the size of the edit box, there are workarounds for that . Finally, for the text formatting, check out chat commands  on the wiki for emotes or out-of-character commands. /em takes out a pencil and brandishes it threateningly. keithcurtis' character takes out a pencil and brandishes it threateningly. /ooc I could really use another coffee right now. keithcurtis:  I could really use another Red Bull right now.

Unfortunately those still have issues, /ooc gives no easy visible distinction between in and out of character and while /em *does* give a visible distinction, you'd have to actually read the line to tell if it's being used as a character action or someone saying they need to use the bathroom.  I guess I'll have to settle for the text box, since Roll20 doesn't seem to support what I'm trying to get.

You could also use markup *italics* and **bold**, if that helps any. There are scripts that could handle the formatting, such as powercards, but that would require a subscription.

For the /ooc, it works best if you set your speaking as to your character, then when you use /ooc the avatar next to the message is different.

You could make something that stands out with the default Roll Template, but not without some extra closing bits: &{template:default}{{name= I could really use another coffee right now. }} Any of this is trivial with the API, but that requires a game whose creator is an active Pro subscriber.