Actually, they're already in a logical order, but perhaps it wasn't apparent. The order was the reverse of what might be expected. A more conventional order in column E would be gained by:
=CHAR(D1)&CHAR(C1)&CHAR(B1)

Alternatively, you could put the whole catastrophe into a single formula:
=CHAR(MOD((ROW()-1)/1296,36)+22+(MOD((ROW()-1)/1296,36)<26)*43)&CHAR(MOD((ROW()-1)/36,36)+22+(MOD((ROW()-1)/36,36)<26)*43)&CHAR(MOD(ROW()-1,36)+(MOD(ROW()-1,36)<26)*43+22)

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]