This almost worked for me.
codeblocks.exe --file="C:\Temp\this.is.a.file"
It got a CB error of
---------------------------
Error
---------------------------
Could not open file C:\Temp\this.is.a.file,
because no extension handler could be found.
---------------------------
OK
---------------------------
I get the same error with this.
codeblocks.exe --file=C:\Temp\this.is.a.file
Windows 7 32 bit.
Added c file extension and this command worked on opening it in CB
codeblocks.exe --file=C:\Temp\this.is.a.file.c
Tim S.