The current preferred HRT prescribed by many physicians appears to be transdermal estradiol plus oral micronized progesterone if the uterus is intact. The preferred starting time is within 10 years post menopause with exceptions. The presenter in this video talked about HRT usage in the management of osteopenia/osteoporosis:

My impression from different readings is that estrogen could be used as an antiresorptive (among its other benefits to the bones), but it's not as strong as say, alendronate/fosamax or reclast.

Please keep us posted regarding your endeavors in using HRT, and whether or not you will use bone markers to monitor progress.

All the best!