Can I write a letter to the judge asking if......?

See, my husband--we have been separated for over a year--is going to be sentenced for burglary this coming month. He really needs rehab because the reason he was stealing was to feed a growing meth habit. This is the reason we got divorced, but I would want to see him get help instead of going to prison to learn new tricks. So, My question is that would I be able to write a letter to the judge presiding that he does in fact need rehab, even though he's never had a drug conviction? The rehab center he applied for has already sent him a letter for an interview, he just needs the judge to say okay. Right now, he's looking at doing 16 years, that was the plea bargain they offered. My two kids can't go fatherless for that long!! Advice anyone??