Converting VMS C to Windows C++ or C#

I have been given a project originally written in VMS C. It is
extensive code, with a number of complex algorithms. It also accesses
an Oracle database via Embedded SQL.

The code is to be ported to a Windows Server 2003 environment. The
database will be ported to Microsoft SQL Server.


I have a couple of choices:

The most ideal choice from a long-term standpoint is to convert the
code to C# and use OLEDB to access the database. Everythings going to
C#, as far as I can see. I have also used OLEDB in VB applications so
I am familiar with it. The downside is that there is no "nice"
conversion from unmanaged C code to C#. I see a number of nasty,
unknown gotchas that could pop up. Even if I find a good conversion
package, there would be major work ahead.

The second choice is to convert to C++ and use the standard ODBC
classes (CDatabase, CRecordset) to access the database. This is
somewhat easier, as more of the original code could be carried over.
The downside here is that I'm left with an application that uses a
platform and functions that will be outdated sooner. From what I can
see, ODBC is falling slowly out of use. At least most of the articles
I see on the internet are at least a year old, most are older. I
could be wrong, though.

The operating constraints for the project are that I have some extra
time in for R&D, but not a huge amount. The same applies to the
budget. The project manager does not want to risk getting bogged down
trying to get the newest software to work on the old code. Having
converted one project from VB 6.0 to VB.NET a few years back, I can
testify that what looks like a fairly simple conversion usually isn't.

I would appreciate any recommendations as to which way I should go.