I have a plug-in. This plug-in should get the values seperated by commas from multitext field one by one and stores to an optionset field. And also this plugin should get values(ids) from multitext field seperated by comma and searches the ids one by one in lookup field values. If found (the search operation should be done one by one in a loop;since there will be more thean one id to search), the value should be seen in the lookup field. After theese opertaions the plugin should save the entity.
How can i do this in crm 2015 using c# visual studio plug-in? Can anyone help me please