KACE Product Support

I've created a custom ticket rule to notify the owner when a ticket is overdue by sending an email. That part works great. Now what I want to do is make the email a little more informative. I am able to include things like category, impact, priority, submitter, etc... but I also want to include information from a custom field in the ticket layout. (I have defined CUSTOM_1 as a single select field with about 30 different possible string values. I want to display the chosen string value)
Reading through posts and KB articles, I came across something that said in order to access the custom field data I need to use the appropriate column, CUSTOM_FIELD_VALUE0,1,2 etc... So, how exactly do I use that within my ticket rule? What do I put it in the query and where do I put it? Also, am I correct in assuming that these CUSTOM_FIELD_VALUE0 corresponds to CUSTOM_1 in the ticket layout?
Any help is appreciated, thanks.