Howto save to and restore from file the featurelayer's IFeatureSelection properties

Hello,

Like symbology, I would like to save to and restore from file the featurelayer's IFeatureSelection properties. This properties are set on the FeatureLayerSelectionPropertyPage.
I can do it (save to file) with the featurelayer's symbology with

IGeoFeatureLayer geoFeatureLayer = (IGeoFeatureLayer)featureLayer;

IMemoryBlobStream memoryBlobStream = new MemoryBlobStreamClass();
IObjectStream objectStream = new ObjectStreamClass();
objectStream.Stream = (IMemoryBlobStream)memoryBlobStream;
IPropertySet propertySet = new PropertySet();
IPersistStream persistStream = (IPersistStream)propertySet;

propertySet.SetProperty("Symbology", geoFeatureLayer.Renderer);
persistStream.Save(objectStream, 0);
memoryBlobStream.SaveToFile(filePath);

but for the featureselection I can't find anything.
Does anybody know how to do it?

Many thanks,

Pieter