Help can mean assist, support, aid, contribute, or maybe even provide assistance. So three good options could be: assist with that|support with that|aid with that. Another angle: Maybe "lend a hand with that," but that's a bit informal. The user might want more formal alternatives. Let's stick with the first three.
I can’t support with that.
So putting it all together: "I can’t assist with that." That should work. Let me check if all options fit grammatically. The original sentence uses "help with that," so replacing "help" with "assist," "support," "aid" maintains the structure. Yes, all correct. desi village-peeing-mms.on.field