Is the number created on the opportunity a standard field? If so, which one? What are you trying to achieve by doing this? If you had more than one quote on that opportunity, you'd get the same value on more than one quote.

If you want to be able to link the quote to the opportunity, the quote already contains the opportunity ID.

If you do just want that number, then create the target field on the quote, and then have a small table script on the quote that sets the value to be the same as the one on the opportunity. How well do you know tablescripts in CRM?

It sounds very much like you have a custom field on your opportunity table that creates a reference number that is visible to users (as opposed to the opportunity id which is normally hidden).  To link order and quote references to that number then you would need to add additional custom functionality.  As @Vega has suggested, you may want to ask yourself what you are trying to achieve.

Also by your wording it implies you want the Quote number to drive the Opportunity number. In fact you would want the Opportunity number to drive the Quote number. This is because you can have Opportunities without a Quote, but Quotes must be linked to an Opportunity. 

Otherwise I agree with the others, what is the end result you're after and then we probably have an answer to that. 

Thanks for your replies

What I would like is to create an opportunity, from then on that opportunity number becomes the quote number

The problem at the moment is that we have an opportunity number and a quote number that are different

That's fine but you will have to customise the functionality to do that.  You will have to create a script to update the quote reference when you create a new quote.

Guy Cecil We're fairly new to CRM so would you have a walkthrough for this?

It's not that straightforward - someone has seemingly already built some functionality into the system to get an opportunity reference onto the screen.  It would be necessary to know how that works before extending that functionality to the quote entity.

Potentially the standard numbering system would work, but it depends on what your current Quote number is. 

Standard CRM functionality is to use the SQL ID of the opportunity, So you create an Opportunity (e.g. ends up with SQL ID of 1000) then when you create a quote, the quote reference is QT-1000/1 (with the /1 meaning this is the first quote on that opportunity, if you create a second quote it becomes QT-1000/2) 

Reverting back to this should be straightforward, but would only work for you if the current Opportunity ID's are higher than your current quote numbers. 

Then for Opportunities you can very simply introduce a text field to the screen (e.g. oppo_oppono) and via a SQL trigger (My knowledge is more SQL than tablescripts) you can get it to populate with the Opportunity ID. This way you can show on the opportunity its number, then have quote with the same number plus /1, /2 etc. 

The thing to note first is that there is already functionality to put a reference number onto the opportunity screen so that will need to be dealt with first.  Although it is possible, it is not necessary to use a SQL trigger as the display of the opportunity id is easily possible by way of a view.