there are two ways of doing this; one being with a rank, which looks much neater, and one for those rankless.
without a rank, you can simply type in chat:
Hello, how are you? *they'd wave at the person*
with a rank, you can use colour codes, to do something that looks neater in chat, such as:
/me &fsays "Hello, how are you?" &e(or any other color code)they'd wave at the person.
basically without a rank, you can action anywhere mid-speech using asterisks. this looks quite messy, although it works.
with colour codes, the same applies though it looks much neater, along with much more customisation.