You can convert the PG SFZ instruments into a GM SF2 with Polyphone http://polyphone-soundfonts.com/en/ or Viena http://www.synthfont.com/Downloads.html then you can load it into SynthFontVST.
If you use Polyphone > Open > C:\Program Files\PG Music Inc\Band-in-a-Box Sounds\Programs in top left search box enter ".sfz" select all > open
You will need to set the patches GM Bank and Preset numbers.
Once saved as SF2 it should load into you default synth > SynthFont, you can also still change each instrument to another SF2.
http://www.synthfont.com/soundfonts.html

https://www.dropbox.com/s/x8ooi4cupvd86b9/BB-SynthFont-CS12M.mp4?dl=0
Click No Thanks Continue at bottom

You can put something like CS12M Master on the Combo FX http://www.vst4free.com/free_vst.php?id=1052

with Compifont http://pphidden.wixsite.com/compifont in Sythfont as default synth.

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