I had a similar problem and I had to use windows :-(.
If you are working with small-ish VCF files you can use R to work with the data (e.g., split it)
To load the file use:
v <- read.table(file,sep='t',header = T,fileEncoding="utf-16")
The UTF-16 encoding was particulary hard to troubleshoot. Eventually Notepad++ helped me to detect this encoding problem.
It correctly ignores the header lines and detects column headers as well.
to remove the columns (except 1 genome) use this command:
in my case the file had 9 initial columns and column 10 had the first genome.
You can modify this to filter genomes 12,13, etc...