How to add message to error log in IP30

Hi guys,

I need to change plant to maintenance plant in order. And, there will be a validation that checks if the material is available in the maintenance plant. If it's not available, I need to add error message to error log when run in background from IP30.

The question is, how to add this message to that error log in IP30? I need clues on error table name or enhancement, or anything.

Thanks before.