I don't have anything ready-made for DT_INTs like that.

But this program has a routine to calculate the timer ticks required to produce a given frequency at a given dutycycle.

Slow speed Software PWM
http://www.pbpgroup.com/modules/wfse...hp?articleid=6

Just use the SetSPWM and CalcSPWM routines.
The interrupt portion isn't compatible with DT_INTS.

HTH,