question about format

[dxs@evolving.com (Dan Stanger)]

i want to use format to concatonate 3 strings in a fixed length field.
for example:
(format nil "~16a" (format nil "~A~A~A" "123" "456" "123"))
"123456123       "
however in the above example i need to do 2 formats, one to concatenate
the strings, the other to put it into a fixed length field.
is is possible to do this with one format call?
thanks,
dan stanger
dxs@evolving.com