Looks like a regression from 4d949990 where for
every other case we did...

-    XubString aRes;
+    ::rtl::OUString aRes;
     aTmp.eType = SbxSTRING;
-    aTmp.pString = &aRes;
+    aTmp.pOUString = &aRes;

while for this case we did only...

     SbxValues aTmp;
     XubString aRes;
     aTmp.eType = SbxSTRING;
-    aTmp.pString = &aRes;

Change-Id: I106cfbcc0fc0b27a9adcbb243d0d69c65b167005