Conflicto de PIC y LCD en PORTC

Estoy trabajando en un proyecto PIC para conectarlo a una pantalla LCD en modo de 4 bits. Mis líneas de datos para mi LCD están conectadas a mi PORTC (PORTC0-3), pero necesito 4 pines de PORTC para conectar también a 4 interruptores (PORTC4-7). El PIC es un PIC16F886. El código para mi LCD.c está abajo.

/*
 *  LCD Interface Example
 *  This code will interface to a standard LCD controller
 *  like the Hitachi HD44780.  It uses it in 4 bit mode, with 
 *  the hardware connected as follows (the standard 14 pin
 *  LCD connector is used):
 *
 *  PORTC bits 0-3 are connected to LCD Data Bits 4-7 (High Nibble)
 *  PORTA bit 2 is connected to the LCD RS input (Register Select)
 *  RW input (Read/Write) is connected to Ground
 *  PORTA bit 1 is connected to the LCD EN bit (Enable)
*/

#include    <htc.h>
#include    "lcd.h"

void pause (unsigned short usvalue);            //Establish pause routine function

#define LCD_RS          RA2
#define LCD_RW          RA4
#define LCD_EN          RA1
#define LCD_DATA        PORTC
#define LCD_STROBE()    ((LCD_EN = 1), (LCD_EN = 0))
#define  DelayS(T)              {unsigned char i; for (i = 0; i < T * 10; i++) __delay_ms(100);}    //Delay Macro
#define  _XTAL_FREQ             4000000

/*Write a byte to the LCD in 4 bit mode*/

void
lcd_write(unsigned char c)
{
    __delay_ms(1);
    LCD_DATA = ((c >> 4) & 0x0F);
    LCD_STROBE();
    LCD_DATA = (c & 0x0F);
    LCD_STROBE();
}

/*Clear and Home the LCD*/

void
lcd_clear(void)
{
    LCD_RS = 0;
    lcd_write(0x1);
    __delay_ms(2);
}

/*Write a string of characters to the LCD*/

void
lcd_puts(const char * s)
{
    LCD_RS = 1;                                 //Write Characters
    while(*s)
    {
        lcd_write(*s++);
    }
}

/*Write one character to the LCD*/

void
lcd_putch(char c)
{
    LCD_RS = 1;                                 //Write Characters
    lcd_write(c);
}

/*Go to the Specified Position*/

void
lcd_goto(unsigned char pos)
{
    LCD_RS = 0;
    lcd_write(0x80 + pos);
}

/*Initialize the LCD - put into 4 bit mode*/

void
lcd_init()
{
    char init_value;

    ANSEL = 0;                                  //Disable Analog Pins on PORTA

    init_value = 0x3;
    TRISA = 0;
    TRISC = 0;
    LCD_RS = 0;
    LCD_EN = 0;
    LCD_RW = 0;

    __delay_ms(15);                                 //Wait 15ms after Power applies)
    LCD_DATA = init_value;
    LCD_STROBE();
    __delay_ms(10);
    LCD_STROBE();
    __delay_ms(10);
    LCD_STROBE();
    __delay_ms(10);
    LCD_DATA = 2;                               //Four Bit Mode
    LCD_STROBE();

    lcd_write(0x28);                            //Set Interface Length
    lcd_write(0xF);                             //Display On, Cursor On, Cursor Blink
    lcd_clear();                                //Clear Screen
    lcd_write(0x6);                             //Set Entry Mode
}

¿Hay alguna forma de "romper" el PORTC para que pueda usarlo tanto para la pantalla LCD como para los interruptores?

Gracias por la ayuda proporcionada.