The CTC format was deprecated back at VS2008. Yes, there is a converter available from convert from CTC to VSCT. Covered by this MSDN page. Read the page for instructions, I'll just outline that page here. You need to obtain the Perl runtime. Then you can run the ConvertCTCToVSCT.pl script located in the VisualStudioIntegration\Tools\bin subdirectory from the command line:
c:\pathto\perl.exe "c:\pathto\ConvertCTCtoVSCT.pl" PkgCmd.ctc PkgCmd.vsct
Where pathto are the paths to the respective files.