You might just try a regular old saw blade. It's slow, but you will be less likely to mess it up. If you have a lot of inward curves it wouldn't work though (can't get the saw blade in there).
Also, I often cut my t-molding groves with a skill saw. It's not too hard if you already have a smaller grove cut. Of course I'm pretty good with a skill saw so your mileage may very.
Honestly, I think your best bet will be to get a dremmel tool, just cut slowly. If you mess-up on a small section it's not a big deal. If you mess-up on a larger section use a glue gun to get the t-molding to stick.
Disclaimer: The above methods are NOT used on DA arcades. We have a CNC router do all the hard work!