txtcon32 is a Test Container for ActiveX controls.
The ActiveX Text Container tool is available as a sample in Visual Studio 2008 and Visual Studio 2010. It is included in the Visual C++ samples ZIP file included with Visual Studio:
For VS2008, it’s in [Program Files]\Microsoft Visual Studio 9.0\Samples\1033\AllVCLanguageSamples.zip
For VS2010, it’s in [Program Files]\Microsoft Visual Studio 10.0\Samples\1033\VC2010Samples.zip
The sample is named TSTCON and is in the C++\MFC\OLE\TstCon folder in the ZIP file. You can build this sample and run it to test the functionality of your ActiveX controls.
You can download the 2010 samples from http://archive.msdn.microsoft.com/vcsamples
If you just need this particular sample, you can download from http://archive.msdn.microsoft.com/vcsamplesmfc
Documentation for tstcon32.