c语言部分：
#include <stdio.h>
#define MAXLEN 16384
FILE *f;
long offset=12345;
long len=678;
char str[MAXLEN];
void main(int *p1,int *p2,char *msg,char *str1[MAXLEN]) {
    //char *msg="D:\\WisePOM_base\\rawsitedata\\20150211\\001@20150211165316.txt";
    //char *str1[MAXLEN];
    char str2[MAXLEN];
    //int *p1 = 0;
    //int *p2 = 888;
    int n = (int)p1;
    int m = (int)p2;
    strncpy(str2,msg,sizeof(str2));
    f=fopen(str2,"rb");
    fseek(f,n,SEEK_SET);
    fread(str,1,m,f);
    fclose(f);
    str[len]=0;
*str1=str;
printf("%s",*str1);
system("pause");
return *str1;
}

用以上程序生成动态链接库
R语言部分：
s=0
l=888
str1="D:\\WisePOM_base\\rawsitedata\\20150211\\001@20150211165316.txt"
str1=""
list1=.C("main",s,l,str1,str2)