[Visual Basic 6.0]
' Get a reference to the first layer in the map

  Dim pMxDoc As IMxDocument
  Set pMxDoc = ThisDocument
  Dim pMap As IMap
  Set pMap = pMxDoc.FocusMap
  Dim pFLayer As IFeatureLayer
  Set pFLayer = pMap.Layer(0)
' Set the definition query of the layer
  Dim pFLDef As IFeatureLayerDefinition
  Set pFLDef = pFLayer				 ' QI from the FeatureLayer
  pFLDef.DefinitionExpression = "SUB_REGION = 'Pacific'"    ' set the definition expression
  pMxDoc.ActiveView.Refresh                                	 ' refresh the map
  
' Make a selection on the Layer

  Dim pQueryFilter As IQueryFilter
  Set pQueryFilter = New QueryFilter
  pQueryFilter.WhereClause = "Pop2000 > 5000000"            ' set the query filter
  Dim pFSel As IFeatureSelection
  Set pFSel = pFLayer
  pMxDoc.ActiveView.PartialRefresh esriViewGeoSelection, Nothing, Nothing
  pFSel.SelectFeatures pQueryFilter, esriSelectionResultNew, False          	' apply the selection
  pMxDoc.ActiveView.PartialRefresh esriViewGeoSelection, Nothing, Nothing   ' refresh the selection
 
' Create a new selection layer using the current selection
 
  Dim pSelFLayer As IFeatureLayer
  Set pSelFLayer = pFLDef.CreateSelectionLayer("Selection_Layer", True, vbNullString, vbNullString)
  pFSel.Clear               	  ' clear selection on original layer
  pMap.AddLayer pSelFLayer   ' add new layer to the map

[Visual Basic .NET, C#, C++]
No example is available for Visual Basic .NET, C#, or C++. To view a Visual Basic 6.0 example, click the Language Filter button in the upper-left corner of the page.