.bat file scripting

Hey, I've been working on a .bat file that evaluates an expression  the user enters into the program. The problem i am having is when I enter an expression into the program it wont display the answer.
Here's my code:
@echo off
Title Calculator
Echo Welcome To Command Prompt Calculator
Echo Copyright Eric Bracht 2008
pause
:A
setlocal
cls
Echo The Time is
Time /t
Echo The date is
Date /t
Set /p C=Calculate:
cls
Set /a %C%
If errorlevel 1 echo Error (level 1)
If errorlevel 2 echo Error (level 2)
pause
goto A
Thanks

i didn't realize you could do such a thing with .bat files.
well i suppose you learn something every day then

Read SICP

GOTO CONSIDERED HARMFUL

>>1
It looks like SET /A just doesn't work from inside a batch file.

Z:\>SET /A 2+2
4
Z:\>COPY CON TEST.BAT
SET /A 2+2
^Z
        1 file(s) copied.

Z:\>TEST

Z:\>SET /A 2+2

Z:\>

>>5
EXPERT BATCH SCRIPTER

>>6
I wish.  It's machine code.

>>1
Nice consistency with capitalisation there.

>>8
I got hard.

I'm quite sure you didn't copyright that batch file.

>>10
I'm quite sure copyright isn't a thing that can be “done”.

I'm pretty sure you can't copyright code of this magnitude. It's so trivial it's like trying to copyright hello world

/*  Hello world - try to output "Hello, world!" followed by a newline
    Copyright (C) 2008 RMS Matthew Stallman

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>;.
*/

#include <stdio.h>
 
int main(void)
{
    return puts("Hello, world!") == EOF;
}

RMS Matthew Stallman
I see what you did there.

>>14
I don't :(

>>15
That is why you fail.

>>16
You have been caught flailing the game

>>13
i lol'd hard

The DARKNESS BIND THEM.

>>17
flailing the game
the game

Back to /b/, please.

The likely lifespan of   your country Kudos.

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