you need to install opal volume control first,then you can change htcvolumecontrol.dll with your fave speaker icon,or make your own...Cab attached in post #56.Thats how I did it,may be there is a better way..
http://forum.ppcgeeks.com/showthread.php?t=56207&page=6
Dont forget to click the green button!
By the way,you dont have to start new thread for every icon in the task bar.
If you using official 6.1 ROM,the easiest way to have battery icon with %on top is to install "quick menu" application.
If you using custom ROM, ask chief ,he should know,I think
if you cook your own,come back here for more info