Set Variable [$date; Value: "=" & Get(CurrentDate)-1]
Perform Find [Restore] where Restore is ICU::Date [$date]
Set Error capture [on]
Constrain Find [Restore] where Restore is ICU::Room#  - this contrains the find to the record that was present yesterday in room 375.
If [ Get ( FoundCount ) ]
Set Field [ICU::Room# ; 375 ]
Note: I wouldn't actually put 375 into either script step where this is listed literally. That requires changing the script each time you need to do this with a different room3. If you use a variable for the room number, this script can then be modified to work with any specified room.
Thanks much Phil,
I was workiing on this today and it looks like your solution is similar to what we were working on. I'll give it a try.