You can convert the first 4000 bytes (depending on version) of the CLOB to varchar2 using PL/SQL.
This link provides some solutions (in PL/SQL)
http://stackoverflow.com/questions/12860526/how-to-convert-clob-to-varchar2-inside-oracle-pl-sql[
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I presume you are already using VC++ to interact with your oracle database so just call the sql as you would any other, or set up a function/procedure to do it and call that from your project
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[EDIT]
I have since found an example where a CLOB has been split into a collection of varchar2 which might be more helpful than my original answer.
https://community.oracle.com/thread/2438977[
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