Parse output of mode con command using FOR /F. Note: must escape pipe symbol | with caret ^.
@echo off
for /f "tokens=1-2" %%A in ('mode con ^| find "Columns"') do set colwide=%%B
echo This console is %colwide% columns wide.
pause
Output of batch:
C:\>colwidth.bat
This console is 104 columns wide.
Press any key to continue . . .
Complete output of mode con
C:\>mode con
Status for device CON:
----------------------
Lines: 9001
Columns: 104
Keyboard rate: 31
Keyboard delay: 1
Code page: 850
Note: Height is height of buffer, not height of window.