This plugin was originally intended to create a winamp position bar that updated pixel by pixel using custom characters rather than 1 character at a time. It is useful for any horizontal progress bar, however. It has three functions (3 different looks).
Function 1 looks much like the built in progress bar, but it uses a custom character instead of the + sign to allow for more frequent updates and more continuous movement. It requires only 1 custom character. This allows you to leave your other 7 custom characters available for other purposes. Parameter 1 of the function is the length of the bar to create and the custom character number to use, delimited by the # character without any spaces. Both are required parameters. Parameter two is the current time and the total time, again delimited by the # symbol. For example, for a 10 character long winamp bar that uses custom character 3, you could use the following:
$dll(Pbar,1,10#3,$Winamppos#$WinampLength)
Function 2 fills in the bar as it continues across the screen. It is framed well by square bracket characters. It uses 2 custom characters (a full block and a dynamic character that represents the current position). They are always # 7 and 8. The first parameter is the length of the bar, while the second is the total length. For the winamp example above:
$dll(Pbar,2,10,$Winamppos#$WinampLength)
Function 3 creates a gapless horizontal bar for CF displays. The bar itself uses 3 custom characters (6,7, and

$CustomChar(1,1,1,1,1,1,1,1,1)$Chr(176)
On the left and
$CustomChar(2,32,32,32,32,32,32,32,32)$Chr(158)
On the right.
For example, to create a 10 character framed gapless winamp position bar, use:
$CustomChar(1,1,1,1,1,1,1,1,1)$Chr(176)$dll(PBar,3,10,$Winamppos#$WinampLength)$CustomChar(2,32,32,32,32,32,32,32,32)$Chr(158).
Along with the mem plugin and getnum plugin, this was also used to create my nero status bar as follows:
$CustomChar(1,1,1,1,1,1,1,1,1)$Chr(176)$dll(PBar,3,18,$dll(getnum,1,$dll(mem,1,0,0),)#100)$CustomChar(2,32,32,32,32,32,32,32,32)$Chr(158)
I hope this is useful!