Write multiple bytes on i2C for lightware rangefinders

I’m attempting to query the first and last return on a lightware range finder, to do this the documentation says I need to send this command on the i2C bus, “?LDF,1” and this “?LDL,1”. I’m trying to use the write command “write_register” but I don’t know how to include all the relevant bytes into one message, if I call multiple write_register commands it just sends the message in distinct data frames which doesn’t trigger the right behavior. Can someone help me with the lua script i2C api or better yet help me find a better way to return rangefinder readings to the lua script?