MS-DOS .com file -, 30 bytes

0000   fc be 82 00 b4 02 ac 88 c2 cd 21 ac 3c 0d 74 0d
0010   b2 28 50 cd 21 5a e8 f0 ff b2 29 cd 21 c3

The string is passed to the executable using the command line. (One space character between the .COM file name and the string).

The result is written to standard output.

The disassembly is here:

  fc          cld              ; Make sure DF is not set (lodsb!)
  be 82 00    mov    si,0x82   ; First character of command line args
  b4 02       mov    ah,0x2    ; AH=2 means output for INT 21h
  ac          lodsb            ; Load first character
  88 c2       mov    dl,al     ; Move AL to DL (DL is written to output)
recursiveFunction:
  cd 21       int    0x21      ; Output
  ac          lodsb            ; Get the next character
  3c 0d       cmp    al,0xd    ; If it is "CR" (end of command line) ...
  74 0d       je     doReturn  ; ... return from the recursive function
  b2 28       mov    dl,0x28   ; Output "(" next...
  50          push   ax        ; ... but save character read first
  cd 21       int    0x21      ; (Actual output)
  5a          pop    dx        ; Restore character (but in DL, not in AL)
  e8 f0 ff    call   recursiveFunction  ; Recursively enter the function
doReturn:
  b2 29       mov    dl,0x29   ; Output ")"
  cd 21       int    0x21
  c3          ret              ; Actually return

Note: You can exit a DOS .COM file (unlike files with EXE headers) using a "RET" instruction.