This command (in a batch file ONLY) should do the trick:
for /f "tokens=2 delims=:" %%a in ('ipconfig ^| find /i "IP Address"') do @Echo %%a
If you want to put it in an environment variable, then:
for /f "tokens=2 delims=:" %%a in ('ipconfig ^| find /i "IP Address"') do @set IPAddress=%%a
Run outside of a batch file, you'd need to remove change all %%a to %a