There is no way in mirc to simulate a new line in the way you want it too. Other than playing to the channel line by line, you could play to an alias which appends each line to the previous line (using a var) then msg that to the channel. Sample output:

<ConfuzzedBot> Current Work Unit ------------------ Name: p753_vln2.8nopbc Download time: September 16 15:22:37 Progress: 6% [__________]

That will work thats better then the way it is now because it basicly spam's the room. How would i go about doing that?