In a similar situation in my skint student days I learnt Fortran from scratch in a couple of days for an interview once and got the job. Most computer stuff you can easily learn enough in a weekend to be able to at least program whatever silly thing they ask you in the interview.
Although since discovering what a joy it isn’t to have a job programming in Fortran on a super-computer that doesn’t even have a proper text editor, I’ve only gone for jobs since when I knew it wasn’t going to be complete dullsville if I got the job.
I didn’t actually lie about anything to get that one though, just applied for the job, said to the first person that I could do the job (which was true, and all they asked), and then made sure I had some knowledge of Fortran by the interview.
Joe