Oracle column differences like a UNIX "diff" command

In an Oracle database, there are two columns in two different tables of the same type - VARCHAR2(4000). The columns are basically a pseudo code.  The columns contain lines of code with embedded line returns.

The need is to be able to determine the difference between the two columns, lines modified, new lines, and deleted lines.  The results becomes a basic UNIX command “diff” of the two columns.

The code needs to be able to report the differences on demand from a Visual Studio 2008 C# application.

Example:

Table 1 column:

--      02073 ALLTEL
NET_CYCLE_TXT            :=  'Changed - NETWORK IS BILLED ON A CURRENT CALENDAR MONTH' ;
NET_CRX_L1_CH            :=      5000.00;
NET_CRX_L2_CH            :=      4250.00;
NET_NET_L1_CH            :=        900.00;
NET_NET_L2_CH            :=      1850.00;
NET_TOT            :=      NET_CRX_L1_CH + NET_CRX_L2_CH + NET_NET_L1_CH + NET_NET_L2_CH;

--Special Message Text--
NET_SPBILL_3_TXT      := 'INSTALL/DISCONNECT DATE REFLECTED IN CHARGE LINE - CHARGES ARE PRORATED BASED ON DATE';

ZGD_NET            :=      NET_TOT;

Table 2 column:

--      02073 ALLTEL
NET_CYCLE_TXT            :=  'NETWORK IS BILLED ON A CURRENT CALENDAR MONTH' ;

NET_CRX_L1_CH            :=      4250.00;
NET_CRX_L2_CH            :=      4250.00;
NET_NET_L1_CH            :=        900.00;
NET_NET_L2_CH            :=      1850.00;
NET_EDT_L1_CH            :=      500.00;
NET_EDT_L2_CH            :=      1500.00;
NET_TOT      :=      NET_CRX_L1_CH + NET_CRX_L2_CH + NET_NET_L1_CH + NET_NET_L2_CH +           NET_EDT_L1_CH + NET_EDT_L2_CH;

--Special Message Text--
NET_SPBILL_3_TXT      := 'INSTALL/DISCONNECT DATE REFLECTED IN CHARGE LINE - CHARGES ARE PRORATED BASED ON DATE';

ZGD_NET            :=      NET_TOT;