how to add contact into the OE group?

[shuqin he]

Hi, i am developing my application using C++ with the help of NKT
WAB .And i've downloaded the NKT WAB V2.1.0 Source Code.
The problem is that i don't know how to add contacts into my OE group
in my application, although i see in the source code that it is
appending the EntryId of the existing contact to the DistList.
Now i can get the DistributionListArray by the property of
PR_DISTLIST_ENTYRIDS and then create the new "lpProp" of LPSPropValue
type.
So how can i set the new "lpProp" as the value of the tag
"PR_DISTLIST_ENTRYIDS" of my OE group? In the source code, it is done
by "SetField(lpProp)" and i am puzzled by the global varialbe
"_changeProps" of "PropMap" type in the function of SetField();
because i can't find any initalization of the varialbe "_changeProps"
in the context. Is it releate to COM? but i know little about it....
So the key is that how can i retrieve "_changeProps" ? if i get it,
maybe i can i set the new "lpProp" as the value of the tag
"PR_DISTLIST_ENTRYIDS" of my OE group. Addtional, it failed when i use
"lpDistList->SetProps(1, lpProp, NULL)" ;
So Could you please give me some tips about that? Thanks a lot~~

The below is my C++ source code of this part:

if(lpContactEntryID)
{
HRESULT hr = E_FAIL;
LPSPropValue lpOldProp;
LPSPropValue lpProp;
SBinary *lpBin, *lpOldBin;
SBinaryArray *lpOldValue;
int cValues = 1;
ULONG arraySize = 0;

lpOldProp = GetDistributionListArray(lpDistList);
lpOldValue = &lpOldProp->Value.MVbin;
if(lpOldValue)
{
cValues = lpOldValue->cValues + 1;
lpOldBin = lpOldValue->lpbin;
}

hr = m_lpWABObject->AllocateBuffer(sizeof(SPropValue), (LPVOID *)
&lpProp);
hr = m_lpWABObject->AllocateMore(sizeof(SBinary)*cValues, lpProp,
(LPVOID *) &lpBin);

lpProp->dwAlignPad = 0;
lpProp->ulPropTag = PR_DISTLIST_ENTRYIDS;

lpProp->Value.MVbin.cValues = cValues;
lpProp->Value.MVbin.lpbin = lpBin;

for(int i=0; i<(int)cValues; i++)
{
if(lpOldValue && i < (int)lpOldValue->cValues)
{
m_lpWABObject->AllocateMore(lpOldValue->lpbin[i].cb, lpProp,
(LPVOID *) &lpBin[i].lpb);
lpBin[i].cb = lpOldValue->lpbin[i].cb;
memcpy(lpBin[i].lpb, lpOldValue->lpbin[i].lpb, lpOldValue->lpbin
[i].cb);
}
else
{
m_lpWABObject->AllocateMore(cbContactEntryID, lpProp, (LPVOID *)
&lpBin[i].lpb);
lpBin[i].cb = cbContactEntryID;
memcpy(lpBin[i].lpb, lpContactEntryID, cbContactEntryID);
}
}
if(lpOldProp)
{
m_lpWABObject->FreeBuffer(lpOldProp);
}

hr = lpDistList->SetProps(1, lpProp, NULL);