making named lexical variables?

[Christian Soeller]

Hi,

I would like to set named 'my' variables by a sub routine, i.e.
something like

 sub foo {
   setargs('a','cdef');
   print $a+$cdef;
 }

being equivalent to
 sub foo {
   my ($a,$cdef) = @_;
   print $a+$cdef;
 }

In other words, is there some straightforward way to create a named
lexical variable via XS that can then be accessed at the perl level? 

Thanks for any pointers.

  Christian