Is there a way to recompile or relink the standard CA-Clipper
 libraries to make CA-Clipper fully compatible with the Borland
 compilers?

 No.  Floating point function calls are too tightly coupled with
 the compiler's code generation to allow that to be done.

 It is possible to write BCD replacement functions for the very
 low-level functions that call the floating-point math
 libraries.  (They have names such as __DVADD() and can be found
 in the map file output from any decent linker.)  The problem
 with this approach is that any numeric _literals_ in the source
 code are already embedded into the object code as double-precision
 floats.  There does not appear to be a good way for a replacement
 math library to deal with the fact that sometimes it will be
 handed BCD numerics and float numerics at different times.