Microserver NL40 mini SAS problem

Hi,

I have Microserver NL40 running the RaidXpert software, the drives are connected to the only internal mini SAS port.  I wnat to connect an internal HP DAT SAS drive but dont have a spare mini SAS port.  I am looking to install a PCIe card that has internal mini SAS port but they are all RAID controller cards.  Can i use one of these just to detect the DAT drive or will i have to use the RAID as well?  i want to keep the RAID as it is with the Raid Xpert.  What other options do i have to install another mini SAS port?

Thanks