What I did was go down and ask the security guard in Ramsey County. Turns out in Ramsey County, they have a couple lock boxes at each location. You notify the security person BEFORE passing through security. They call the deputy. The deputy finds the keys. you give them your permit and letter. They lock up the firearm. You have to claim it every time you leave the building.
I don't know if the HCSO has made allowances for this. If they do, my advice is to make SURE you have given notice in writing just in case. Bring a copy of the notice. Bring 2. get the first deputy to initial it receipted and give you their badge number or business card.
dan: just saw your e-mail and replied.