How to get pointers to received OID in GetXXXXXXXXXX functions in XXXXXXXXinstru.c files? Please write example!

/*****************************************************************************
* Function Name : GetMgIndex()
*
* Args : 1. Pointer of the entry (IN).
* 2. Pointer of the variable value length (OUT).
* 3. Status which is used to return SNMP Error (OUT).
*
* Returns : The Current value of "mgIndex".
*
* Task : Get method for (table) column mgIndex.
*
* "A unique value, greater than zero."
*
* See Also : SetMgIndex().
*
* Docs : Yes.
*
* Bugs :
*****************************************************************************/
U_CHAR *GetMgIndex(void *tableEntryPtr, INT32 *varValLen, U_CHAR *status)
{
MgTableEntry *mgTableEntryPtr;

DEBUGMSG1("\n\t@@@@@ Inside GetMgIndex() @@@@@\n");

mgTableEntryPtr = (MgTableEntry *)tableEntryPtr;

/* Please provide your code to instrument "mgIndex" here */


*varValLen = sizeof(mgTableEntryPtr->mgIndex);
return (U_CHAR *)&mgTableEntryPtr->mgIndex;
}