Here?s a challenge that I can't solve:
The task is to ether to calculate the light of a shadow from a tall building (church) and it's direction (preferably azimuth in degrees) or to calculate a precise position of the tip of the shadow (GPS coordinates). The parameters are as follows:
- The location of the building is N 57? 23.763 E 021? 34.071.
- the high of the building is 30.5 meters;
- the date and time when the shadow appeared is January 18, 2009 at 11:50 (UTC/GMT 2 hours).
Can anyone help me with this task?

First what you need to determine is the position of the sun from the perspective of an observer at those coordinates at that precise time. Here's a handy site for doing that: NOAA Solar Position Calculator

From the coordinates you provided this church is in Latvia. The time zone is -2 hours GMT, not +2 hours. When I enter position latitide = 57 degrees, 23 minutes, 4 seconds north and longitude 21 degrees, 34 minutes and 4 seconds east with offset to UTC of -2 hours for the date and time you provided the site reports that the sun was at altitude = 11.38 degrees and azimuth = 167.06 degrees. Note the sun is just above the horizon - not surprising for a place that far north in winter.

Can you take it from here?