. You need to catch your problem  at the source,
and that is the user input. By creating  a master  list, that can be
updated and edited by the user, you will be able to organize your data
later.

Personally, I am a believer in using MS-Access with MS-Excel. By placing
this data  into a single repository for user entry, and then exporting it
to Excel for reporting. Either way, your goal is to control the user
input.

Since the different names  reference the same account, we can surmise
that there is data that the two share. By creating a master list, and a
user input form, you can control how the new names are entered. The user
will have to select the account the names are associated with, and
viola! You have a key to link all your data.