Well, you did ask about a VB...
Assuming you can do your merge setup so it outputs:
Code:
firstname lastname@companyname.co.uk
you could then do a
wildcard Find/Replace, where:
Find = (<[A-Za-z0-9]@>) (<[A-Za-z0-9]@>\@[A-Za-z0-9.]{1,})
Replace = \1.\2
to turn all those strings into:
Code:
firstname.lastname@companyname.co.uk
Even so, you wouldn't have clickable email addresses.