The quoted part of your post isn't exactly worded correctly - or at least doesn't make much sense, but to answer your basic question:  Yes, you can.  When you put the drives into the replacement machine and power up, you will want to watch for the CTRL-M prompt to enter the configuration utility for the PERC.  Go to Configure, View/Add, Disk View (if prompted between Disk/NVRAM), then Save the configuration on exit.  That will import the configuration on the disks into the controller, and you should then be able to boot to the OS installed on that array. One thing to note: Ideally, firmware on the source and target RAID controllers should match - if they are VERY different, I would update it to make sure it is the same, or you may experience problems recognizing, importing, and/or using the new configuration.
"Client has a failed 2800 and now has a replacement unit. Drives must be removed from the failed unit and installed in the replacement server. System then needs to be joined to the network and be visable by the raid array". The question is can I move the drives from old 2800 server to replacement 2800 server and attach to the array? Are there any special steps that I need to follow? Any advise or input would be greatly appreciated. Thanks Mario  
PowerEdge 2800