New here and with limited deep programming experience.We have 5 offices in our national group that use VBA written Excel addins (xla files) with UDFs. Each of the 5 offices have their own unique Addin.xla each with their unique UDFs. The plan is to consolidate all the UDFs from the 5 office into one master addin written in ExcelDNA (XLL file) with new UDF names. The 5 offices will run Excel thru a Citrix environment with users from each office having their Excel Citrix setup with their respective old addin and the new master addin. Since the 5 offices have old workbooks, the old addins will have to remain available for a while so the older workbooks which contain old UDFs still function. I have the new master addin.xll written and functioning with the older addins. We will want users to abandon the old UDFs and use the new UDFs in new workbooks so I’m looking for a solution to discourage users from using the old UDFs – the old UDFs must be available for to allow old workbooks to function. Any ideas?