I created few custom fields in Opportunity Product (OpportunityLineItem) Object, values of which I need to have copied to QuoteLineItem when a quote is generated. PricebookEntryId seems to be the only common column in both Objects but it has a many-to-many relationship. Ideally, I'd like to modify the logic that generates Quotes to include those new fields, but I think that trigger might have to used instead. Since user can enter more than one line item of the same PricebookEntryId I can't guarantee that values from OpportunityLineItem are copied to the corresponding QuoteLineItem. Any suggestions on how to solve it will be appreciated.

I want to create a child of OpportunitiyLineItem object, say OpportunityLineItemProfitSchedule but there is no option to create the neither master-detail nor lookup relationship to OpportunityLineItem object, i.e.. OpportunityLineItem object is not available in a drop down list of available objects. Is there a different way to set this up?