Hidden Information in .txt/.csv File

Hidden Information in .txt/.csv File

I have been given a .csv/.ssv/.txt file (a semi-colon delimited text
file). If I open this file with a text editor (Notepad++, Notepad,
010Editor et al.) I see data similar to the following subset:
IK; Aufnahmedatum;...;Entlassungsdatum
123456789;2.01201E+11;...;2.01201E+11
where the ellipsis indicates other data.
Now, the formatting is not important; what is important is the 2.01201E+11
scientific formatting. If I attempt to read this .csv file as text I get
2.01201E+11. However, if I first convert my .csv to .txt and then open it
with Excel and use the formatting wizard, I again get cell values with
2.01201E+11 here comes the wired part - if I now edit the cell value, I
see what I want; namely 201111010811. This is a data-time with formatting
'yyyymmddhhmm'.
How does Excel get this information when it does not appear to be in the
underlying .csv/.txt file? How can I get this information without first
converting the file via Excel?
Thanks for your time.