Batch file help needed - functions, variables and substrings

I'm trying to write a batch script for windows XP. It needs to build an IP address from ipconfig by getting the (192.168.XXX.30) XXX part of the address and supplanting it into a template. Then some fun stuff from a network shared folder.

SET _var=ipconfig |FIND "192.168"
SET _var=%_var:~25,-4%

net use z: \\192.168.%_var%.30\test_folder

... Do stuff

net use z: \DELETE

ECHO "Tasks completed"
PAUSE

At the moment I can't seem to get the result from ipconfig in to my variable, would be even better i开发者_如何学Gof I could get the substring from it in 1 line.

Any ideas?

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The first task, per your question, is to get the IP address. To get one from www.google.com:

for /f "tokens=2 delims=[]" %f in ('ping -4 -n 1 www.google.com ^|find /i "pinging"') do echo IP=%f

Say the resulting value of IP is now 192.168.10.20. You can get the third octet of %IP% from a second FOR statement:

for /f "tokens=3 delims=." %f in ("%IP%") do echo ip3=%f

The result from the above statement, given the value of the example, would be:

ip3=10