Help needed to extract character position

[blx]

Hi All,
An easy one for those in the know !!
I have hostnames of machines in my environment that can be displayed as either:

NTSNRTWK006
YSWWKFDS01

I want to be able to extract only machines that have WK as the 7th and 8th characters, and output them to a file.

Any ideas?

Thanks in Advance
Blx

 

[dchoulette]

"the command you use to list hosts"

 | grep '^......WK' > anOutputFile