It's even more complex than you think! The DVC that was incorporated into the Posky -700 and -800 models was originally part of Moach's 737 Experience, used by the Posky team in their -700 and -800 by agreement with the Moach brothers. Only the textures have changed. So I'm not sure that the VC developer can incorporate this DVC into payware products as he would have had to get permission from Moach, as it was originally a freeware product! He might have done: I don't know.
However, you don't need the ex-Posky panel as I think I can point you towards a different one. I use the 737NG panel by Arjan Scheffel, which is better than the ex-Posky one IMHO, and is supplied as part of a package incorporating his repaint of Erick Cantu's 738. (The package is on wspilots.com - as738.zip, 11th down the page here
http://www.wspilots.com/mx/index.php?page=26&action=category&cat_id=2&modrewrite...). I have the VC set up to use default and the Scheffel gauges and it works fine: here are the VC sections for the panel.cfg which might help you.
[Vcockpit01]
texture=$panel
Background_color=0,0,0
size_mm=1024,1024
visible=0
pixel_size=1024,1024
gauge00=AS738!PFD, 98,128,133,160
gauge01=Boeing737-800!MFD, 243,128,133,160
gauge02=Boeing737-800!EICAS, 463,134,124,155
gauge03=Boeing737-800!MFD, 644,128,133,160
gauge04=AS738!PFD, 791,128,133,160
gauge06=737-400!Flaps, 562,54,38,46
gauge07=cessna!OMI_Lights, 300,67,37,16
gauge08=cessna!OMI_Lights, 689,75,38,16
gauge09=737-400!Clock, 27,144,59,76
gauge10=737-400!Clock, 935,144,59,76
gauge11=AS738!Attitude, 394,73,51,53
gauge12=AS738!RMI, 388,230,50,57
gauge13=AS738!AltSpd, 394,148,51,68
gauge14=lear_45!Nose Gear Light, 611,54,19,25
gauge15=lear_45!Left Gear Light, 602,78,19,24
gauge16=lear_45!Right Gear Light, 621,78,19,24
gauge17=737-400!Flaps Ext, 559,101,22,15
gauge18=737-400!Flaps Transit, 580,101,22,15
gauge22=737-400!Pitch Trim, 612, 5, 22
gauge23=Boeing737-NGks!MFDSwitch, 240,85,32,29
gauge24=simicons!Avionics Icon, 560,24,15,14
gauge25=simicons!Map Icon, 576,24,15,14
//--------------------------------------------------------
[Vcockpit02]
texture=$autopilot
Background_color=0,0,0
size_mm=512,512
visible=0
pixel_size=1024,1024
gauge00=AS738!Compass, 469,7,42,38
gauge01=APCRSS, 126,5,15,8
gauge02=Boeing747-400!Autopilot IAS-Mach Window, 171,2,28,13
gauge03=Boeing747-400!Autopilot Heading Window, 206,2,23,13
gauge04=Boeing747-400!Autopilot Altitude Window, 238,2,26,13
gauge05=Boeing747-400!Autopilot VS Window, 263,2,25,13
gauge06=APCRSS, 324,6,15,8
gauge07=Boeing747-400!Autopilot Nav Switch, 225,2,13,13
gauge08=Boeing747-400!Autopilot Hdg Switch, 211,33,11,11
gauge09=Boeing747-400!Autopilot Approach Switch, 227,33,11,11
gauge10=Boeing747-400!Autopilot Altitude Hold Switch, 246,31,11,11
gauge11=Boeing747-400!Autopilot Master Switch, 289,7,11,9
gauge12=Boeing747-400!Autopilot Speed Switch, 162,32,13,11
gauge13=Boeing747-400!Autopilot IAS-Mach Switch, 196,32,12,9
gauge14=Boeing777-300!Master_Caution, 16,22,13,13
gauge15=Boeing777-300!Master_Caution, 439,22,13,13
gauge16=pg.1-11.ap.diseng, 41,22,13,13
gauge17=fsd_warn.stall, 4,22,13,13
gauge18=fsd_warn.overspeed, 29,22,12,13
gauge19=pg.1-11.ap.diseng, 413,22,13,13
gauge20=fsd_warn.stall, 451,22,13,13
gauge21=fsd_warn.overspeed, 426,22,13,13
gauge22=J777.crs, 121,2,26,12
gauge23=Boeing737-NGks!ControlPanel, 57,1,56,47
//--------------------------------------------------------
[Vcockpit03]
Background_color=0,0,0
size_mm=512,512
visible=0
pixel_size=1024,1024
texture=$console
gauge00=737-400!Transponder, 0,345,201,78
gauge01=737-400!Comm 1, 0,0,201,86
gauge02=737-400!Comm 2, 0,86,201,86
gauge03=737-400!Nav 1, 0,172,201,86
gauge04=737-400!Nav 2, 0,258,201,87
gauge05=737-400!ADF, 0,424,201,87
[VCockpit04]
size_mm=512,512
pixel_size=512,512
texture=$Posky_ACU
background_color=0,0,0
gauge01=Posky737!PkyNosegearheight, 140,80,140,80
gauge02=Posky737!PkyLeftgearheight, 140,80,140,80
gauge04=Posky737!PkyRightgearheight, 140,80,140,80
gauge12=Posky737!PkyNosegearsteerling, 140,80,140,80
gauge25=Posky737!Pky_PB_Towhead, 140,80,140,80
These sections incorporate the Posky VC additions to make the XML animations work. Paste these sections after the fixed window sections in the panel.cfg.
If the BBJ2 model doesn't have a VC (and I haven't seen it yet, although I have the download) then unfortunately you can't add one in FS9. However, what you could do is either search for a BBJ repaint for the 737-800 with VC (google is your friend), or re-name the BBJ texture files to match those on the 737-800: it's possible that they'll match up although I haven't tried it.
Let me know how you get on.