Get Return Code C++ in TCL

[biboun]

I have an C++ code was return value for different error.

int main(int argc, char * argv[]) {

error 1 -> return 1 or exit(1);
error 2 -> return 2 or exit(2);
...
}

Question -> How can i get in TCL when I execute the exe file, the return value.

set status [catch {exec ..... } result ] return only if the fonction was successfull execute.

Any idea ? Thanks