I would love to learn more about "DEFINE INTHAND" but would be very happy to get any timer interrupt to work with any method possible at this point.
SecaRider, my hat is off and a knee is bent to respect your tenacity tackling the new K42. For starters, practically all of the latest PIC offerings responded to the tweaks in the PIR/PIE listings for the DT_INTS-xx.bas routines. It was discussed previously that due to the extended memory range, the DT_INTS would require a much more intensive revamp to work with the K42 PICs.

With that said, "DEFINE INTHAND" is a DEFINE that directs the compiler to send the PC (Program Counter) to whatever you specify as your Interrupt Handler. Ultimately, with Vectored Interrupts turned off, that address will be 0x08. Universally agreed upon is the practice of placing your Interrupt Handler as close to the top of your Code Page as possible, with a command, "GOTO MAIN" (or START, or INIT) above your Interrupt Handler Label. DEFINE INTHAND is used only for Assembly Code interrupts. I don't know how proficient you are at ASM. There are work-arounds with w-save variables for "W", "BSR", "STATUS" and maybe some variables. Theoretically you could use INTHAND to go to an Interrupt Handler that uses PBP. The variables probably won't survive the RETURN intact (suggested by more skilled programmers in previous topics). If nothing else, you could INTHAND with your Interrupt Handler to "CALL" (ASM version of GOSUB) another PBP scripted subroutine.

The K42s are different enough from anything else ever created in the PIC 8-bit lineup that they must be treated carefully. I hope this helps point you in a better direction.