Public Property LookupList As String
Dim instance As SPFieldLookup Dim value As String value = instance.LookupList instance.LookupList = value
public string LookupList { get; set; }
SPFieldLookup lookUpField = (SPFieldLookup)list.Fields.GetField(fieldName);lookUpField.LookupField = lookupFieldInternalName;lookUpField.LookupList = lookUpSourceList.ID.ToString();lookUpField.Update();