I believe you can use a excel file with a mail merge in the mail merge
setup. If you record a macro whilst setting up a merge you will be able to
find all
the vb code needed and you can then write a macro that can change the
worksheet .(see SQLStatement:=) in fact you will see a line similar to. I am
sure that you will also be able to find full reference online.

Connection:= _
       "Provider=Microsoft.Jet.OLEDB.4.0;Password="""";User ID=Admin;Data
Source=C:\Book1.xls;Mode=Read;Extended Properties=""HDR=YES;IMEX=1;"";Jet
OLEDB:System database="""";Jet OLEDB:Registry Path="""";Jet OLEDB:Database
Passw" _
       , SQLStatement:="SELECT * FROM `Sheet1$`", SQLStatement1:="",
SubType:= _
       wdMergeSubTypeAccess

regards

Andrew