[R] reading a specific part of a text file into R

I was wondering if it is possible read a specific part of a text file in R without importing whole file. For example, I want to read a number where is located on the line 30 and columns between 2 and 4. Say the number is 456. can I see it without opening the file. I want to learn how to do this be

[R] Running other programs from R

Dear list, I want to run a statistical program (using its .exe file) from R by writing a script. I know there are some packages that call WinBUGS, Mplus etc. form R. I just want to call the .exe extension of this program and run several times writing a code in R. Thus, I want to have the output