Reading specific columns from a fixed width format file

Question

I have large fixed width format dataset with multiple records with record number 1, 2, 3 and so on. I want to read all those records where record number is 1 using the select * sql statement. I'm using read.fwf function to import from the file but how to use sql statements with read.fwf function or any other alternative to read from fixed width format having some condition ?