The proposed solutions worked partially, but need more help.
The original question and non-working answers are here link text
Thanks in advance.
@caliray - If I would now take an hour or two, I would first start with the suggestions made by @oweng and @mariosv. Their suggestions are pretty good and also point to Text Functions of Calc. Thus, let me recommend you to work on their suggestions and show results you got. This would save others time to help you.