I would not try it because attempting to pass money could put the check-in person in a tight spot and may get them fired (although, some stupidity on their part would be required as well).

The problem is that service establishments like to consider tips their own so one needs to be very discreet in order to get money to a speicific employee. I know of no discreet ways to accomplish such at a hotel front desk (under the watch of many cameras).

That said, if you tip well, odds are, you will get great service. And, if you want to go the extra mile, treat the manager (or assistant manager) to dinner/drinks. This gesture will pay dividends on subsequent visits.