Compatibility: 1.0+
Expects: AH    24H
DS:DX address of an opened FCB
                                                                  
Returns: none
                                                                  
Info: Sets the randomRec field of the FCB to the file address that
corresponds to the values of curBlk and curRec.

42H (Lseek handle)
- -

DOS Fn 24H: Set Random File Block Address