I think too much depends on the details...

For example, if I use the two lists  you gave originally:

> GROUP1
> # USRID NAME SALES
> 1 545565 JOHN SMITH 599.0
> 2 105654 NORMAN ANDERSON 599.0
> 3 541586 ANTONIO BANDERAS 599.0
>
> GROUP2
> # USRID NAME SALES
> 1 545563 JANE 599.0
> 2 105654 MIKE 599.0
> 3 541586 STEVE 599.0
> 4 343423 MARK 599.0

I can just do a database query, without a macro, to get create this
output of data:

> F1 F3 F4
> 1 JOHN SMITH 599.06
> 2 NORMAN ANDERSON 599.06
> 3 ANTONIO BANDERAS 599.06
> 1 JANE 599.06
> 2 MIKE 599.06
> 3 STEVE 599.06
> 4 MARK 599.06

But, as they say, the devil is in the details.