I'd be a bit surprised if there was a single CAS number for this - generally they are used to identify single chemicals/substances, whereas the creamer is presumably a composite product containing a variety of materials?
Where is your company based / selling its products? This can have affect the requirements for MSDS information.
For some products it's possible / sensible to list the CAS numbers for the component parts, but this isn't always the case.
If you know what is in the product you can see how feasible this is using one of the various search sites for such things - the following may help:
It's also not unheard of for customers to ask for data that isn't at all relevant to a product, simply because they haven't really thought about it and it's a standard process for them to request x/y/z...