I think this should work, use some time to get through, it is a must to consult SDK, there are a lot examples that are just waiting to be used.
IDataset pDataset = destinationFeatureClass as IDataset;
IEditWorkspace pEditWorkspace = pDataset.Workspace as IEditWorkspace;
//Open Edit Session
try{
pEditWorksapce.StartEditing();
If you got list of FID-s you do as follow:
// spatialreference
IGeoDataset pDestGeoDataset = destinationFeatureClass as IGeoDataset;
foreach(int fid in FIDlist)
{[INDENT]IFeature pFeature = sourceFeatureClass.GetFeature(fid);
IFeature pNewFeature = destinationFeatureClass.Create();
pNewFeature.shape = pFeature.ShapeCopy;
pNewFeature.spatialreference = pDestGeoDataset.SpatialReference;
//set some attribute
int fieldIdx = pFeature.Fields.FindField("attributeName");
pNewFeature.SetValue(pFeature.getValue(fieldIdx));
pNewFeature.Store();
[/INDENT]}
pEditWorksapce.StopEditing(true);// save edits
}
catch(Exception ex)
{
[INDENT] //some alert, log ...
MessageBox.Show(ex.message);
[/INDENT] }
Hope it works if not please let me where you got error. Use try/catch