Well first, make sure you actually have support for the QLogic card. It might be running as a module, usually starting with qlaXXXX, depending on the model you have installed.
Not sure or don't see anything related, could have been built into the kernel. You could get the model maybe from:
You can find out the LUN info by cat'ing the /proc/scsi/<qlogic-device>/<scsi-number>
Then hot adding a LUN should look something like this from the info you get from the previous cat output:
"echo "scsi add-single-device Controller Channel Target LUN" > /proc/scsi/scsi"