Hotel room numbering
CJam, 34 31 bytes

qN/W%zSf-La%{_{s'*&amp;}#_)@@=}3*;\


This requires the input to be padded to a rectangle with spaces.

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Explanation

qN/      e# Read input and split into lines.
W%z      e# Rotate 90° counter-clockwise.
Sf-      e# Remove all spaces from the rows.
La%      e# Split into buildings. We've now got a 3D array of rooms, where the first
         e# dimension is the building, the second the room number and the third is the
         e# the floor number.
{        e# Run this block three times. At each stage it will find the index of the "*"
         e# along the current dimension and leave the element at that index on the stack
         e# for the next round...
  _      e#   Duplicate the current array.
  {      e#   Find the index of the first element where this block yields something
         e#   truthy...
    s    e#     Flatten into a single string.
    '*&amp;  e#     Set intersection with "*".
  }#
  _)     e#   Duplicate the index and increment it, because the results should be 1-based.
  @@=    e#   Pull up the array and the other copy of the index and select the
         e#   corresponding element.
}3*
;\       e# We've now got the building, room and floor index on the stack, as well as the
         e# "*" character itself. We discard the character and swap the room and the floor
         e# floor number. When the three indices are printed back-to-back at the end of
         e# the program, that will yield the desired result.