Bioperl Primer3 Tm calculation of a pre-defined primer

Hi all,
I'm using Primer3 to design primers (Bio::Tools::Primer3). I also need use
Primer3 to calculate Tm for some pre-defined primers; however there is no
direct way to calculate Tm with Primer3. I have to call Primer3 and supply a
pre-defined primer, a template, etc to let it run and hopefully Primer3
finds a pair of primers for me, then I have to open the output and find out
what the Tm is for my pre-defined primer. Do I miss any function that can do
this quickly for me?
I know there's another module (Bio::SeqFeature::Primer) can do this
quickly, but the Tm is calculated with different parameters; therefore it's
not good to use it while I use Primer3 to design primers.
Any input?
Thanks!
-Tony