help in creating a new language with python

[hsunteik]

i am creating my own programming language (the name is codime) interpreter\compiler with python,but every time i want to compile\interpret my script written in my language,i need to go to cmd and key in

first,the directory.
then,run it like this:
python test.py test.codime

test.py(the interpreter create with python)
test.codime(stuff written in my language)

1)how to make it run by just clicking a run button in a text editor instead of needing to go the cmd and write the above comment line  again and again to run it?

2)how do i make it so that the interpreter that i am creating can only interpret file that have the .codime file extension?(like python can only compile file with  .py   extension.

i am a beginner, so please make the answer as detailed as possible   ,but not too long word ,if possible. 
thanks......