Sharing data between apps via DLL

From:

Nondisclosure007 <nondisclosure007@gmail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Sun, 3 Jul 2011 19:02:26 -0700 (PDT)

Message-ID:

<610632c3-73d9-4711-b814-7d8857ecb940@r21g2000pri.googlegroups.com>

How can I do this? I've reseached on Google for about 10 hours, tried
what I found and nothing works.

Dev: Visual Studio 2010 C++
App1: Metatrader 4
App2: Metatrader 4 (Different instance).

I can send data to the DLL, do some math, and send back to the same
instance. That works beautifully. But trying to go in between apps
is getting to be a nightmare.

Can this even be done? If so, how? My C++ is sooooooooo old.

Here's the code that have:
..cpp:
#define WIN32_LEAN_AND_MEAN
#define MT4_EXPFUNC _declspec(dllexport)

//Global variables w/ Global scope in DLL ONLY!
#pragma data_seg (".myseg")
    double varIBFX, varAlpari;
#pragma data_seg()

//For IBFX to put data and get back from Alpari
MT4_EXPFUNC double _stdcall GetValueForIBFXFromAlpari(double
varPutValue)
{
    varIBFX=varPutValue;
    return(varAlpari);
}

//For IBFX to put data and get back from Alpari
MT4_EXPFUNC double _stdcall GetValueForAlapriFromIBFX(double
varPutValue)
{
    varAlpari=varPutValue;
    return(varIBFX);
}

code for .def:
LIBRARY "EURUSD"

EXPORTS
        GetValueForIBFXFromAlpari
        GetValueForAlapriFromIBFX

SECTIONS
        .MYSEG READ WRITE SHARED

I know these don't look like they do much, but I need to get the pass
off to work first. Then I can start the "good stuff".