How can I do a line trace and only check against a specific instance of an object?

[anonymous_user_a2509f6c]

First Go to Project Settings > Collision then create a New Object Channel name it what you want.
Next select object(s) you want to hit with the line trace, go to Collision > Collision presents and change to (custom) then under Object Type select the one you just created.
Finally create a LineTraceForObjects then drag out Object Types to create a custom variable and select the one you created.