VARIANT export/import C++ DLL SAFEARRAY - c++

Question

I know that this topic is quite popular. However, I'd like to solve a simple problem... My target is to create a DLL in C++ able to import and export data matrices from VB (Excel or other programs). I read in some blogs that a common way to do that is to use the SAFEARRAYs.
So, I created the following C++ code:
VARIANT _stdcall ReadArrayVBA_v1(VARIANT *Input0) {
double dm = 0, rm = 0;
//OUTPUT DATA DEFINITION
VARIANT v;
SAFEARRAYBOUND Dim[1];
Dim[0].lLbound = 0; Dim[0].cElements = 4;
v.vt = VT_R8;
v.parray = SafeArrayCreate(VT_R8, 1, Dim);
//==============================================
SAFEARRAY* pSafeArrayInput0 = NULL; //Define a pointer SAFEARRAY Type
pSafeArrayInput0 = *V_ARRAYREF(Input0);
long lLBound = -1, lUBound = 1; //Preset dimension
SafeArrayGetLBound(pSafeArrayInput0, 1, &lLBound);
SafeArrayGetUBound(pSafeArrayInput0, 1, &lUBound);
long CntElements = lUBound - lLBound + 1;
long Index[1];
for (int i=0; i<CntElements; i++){
Index[0] = i;
SafeArrayGetElement(pSafeArrayInput0, Index, &dm);
rm = dm + 1;
SafeArrayPutElement(v.parray, Index, &rm);
}
return v;
}
It compiles and I call from VBA Excel in the following manner:
Private Declare Function ReadArrayVBA_v1 Lib "[PATH]\VARIANTtest.dll" (ByRef Input0 As Variant) As Variant
Sub VBACall()
Dim InputR0(1 To 4) As Variant
Dim vResult1 As Variant
InputR0(1) = 2
InputR0(2) = 20
InputR0(3) = 200
InputR0(4) = 240
vResult1 = ReadArrayVBA_v1(InputR0)
End Sub
The function gives me back values such as 1.2E-305 and similar. Why?