precompose layers and simply updatable progress bar

Hi,  guys, can i return precomposed layers and use this precompose  for add some stuff(name, effects,property and etc)

example

app.project.item(index).layers.precompose(preArray,precomp_name,true); // i precompose layer in this command

in future i need do stuff with that precompose,  so i need way to get precompose

i try use this

var curentPrecomp_layers = app.project.item(index).layers.precompose(preArray,precomp_name,true) ;

curentPrecomp_layers.name //dont work

curentPrecomp_layers.width //dont work

So how i can get my precompose not using loop for finding it by name, or this is only loop??

also can some one give me a example of progress bar script, how create, show,update, hide it

thx.