twNum2Str( nValue, nMantLen, nDecLen )
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     The functions twDec2Sci(), twSci2Dec(), twStr2Num() and
     twNum2Str() attempt to provide a temporary solution to Clipper's
     inability to display floating point numbers.

     twNum2Str() produces a string representation of a numeric value. If
     within range of VAL(), it uses TRANSFORM(), otherwise it uses
     twDec2Sci().

     NOTE: Numbers outside the MSC calculation range will result in a
           MSC error which cannot be trapped with ERRORSYS.

       Arguments:

     nValue   - 'N' Value to transform.

     nMantLen - 'N' Length of the mantissa display. The default is 13.

     nDecLen  - 'N' Length of the decimal part of the display. The
                    default is 10.

       Return:

     String representation of the number passed.

       Example:

     twNum2Str( 34.567 ) -> "           34.567       "