Not quite sure that I understand what you're wanting to check.
I get external surveys pretty frequently, and even when I get an in-house survey, my surveyor is still using AutoCAD 2000 + Eagle Point daily Haha, so all of his drawings open in International Feet (never really understood why, especially when I'm using Imperial, but WTFE).
To know when 'something isn't right' in Civil 3D, I use 'Map Status' (MAPSTATUSBAR Command) to show me what coordinate system I'm working in for any given drawing, and to help expedite setting my desired coordinate system I wrote a lil' ditty for that too... Take from these what you like:
Toggle Map Status
Code:
(vl-load-com)
(defun c:MapStatus ()
(command "._mapstatusbar"
(if
(= 0
(vl-registry-read
(strcat
"HKEY_CURRENT_USER\\"
(if vlax-user-product-key ; If 2013+
(vlax-user-product-key) ; Use new function
(vlax-product-key) ; Use legacy function
)
"\\Applications\\AcMap"
)
"Statusbar"
)
)
"_s"
"_h"
)
""
)
(princ)
)
Set Coordinate Zone
Code:
(vl-load-com)
(defun c:SetCoordinateZone (/ vrsn acApp aeccApp aeccDoc aeccUnitsZone aeccCoordSys coord acDoc)
(defun *error* (msg)
(if aeccApp
(vlax-release-object aeccApp)
)
(if acDoc
(vla-endundomark acDoc)
)
(cond ((not msg)) ; Normal exit
((member msg '("Function cancelled" "quit / exit abort"))) ; <esc> or (quit)
((princ (strcat "\n** Error: " msg " ** "))) ; Fatal error, display it
)
(princ)
)
(if
(and
(setq vrsn
(if vlax-user-product-key ; If 2013+
(vlax-user-product-key) ; Use new function
(vlax-product-key) ; Use legacy function
)
)
(setq vrsn
(cond
((vl-string-search "21.0" vrsn) "11.0") ; 2017
((vl-string-search "20.1" vrsn) "10.5") ; 2016
((vl-string-search "20.0" vrsn) "10.4") ; 2015
((vl-string-search "19.1" vrsn) "10.3") ; 2014
((vl-string-search "19.0" vrsn) "10.0") ; 2013
((vl-string-search "18.2" vrsn) "9.0") ; 2012
((vl-string-search "18.1" vrsn) "8.0") ; 2011
((vl-string-search "18.0" vrsn) "7.0") ; 2010
((vl-string-search "17.2" vrsn) "6.0") ; 2009
((vl-string-search "17.1" vrsn) "5.0") ; 2008
(T nil)
)
)
(setq aeccApp (vla-getinterfaceobject
(setq acApp (vlax-get-acad-object))
(strcat "AeccXUiLand.AeccApplication." vrsn)
)
)
(setq aeccDoc (vlax-get-property aeccApp "ActiveDocument"))
(setq aeccUnitsZone
(vlax-get
(vlax-get (vlax-get aeccDoc 'settings) 'drawingsettings)
'unitzonesettings
)
)
(setq aeccCoordSys
(vlax-get
(vlax-get
(vlax-get (vlax-get aeccDoc 'settings) 'drawingsettings)
'unitzonesettings
)
'coordinatesystem
)
)
(setq coord "FL83-WF")
(princ "\nWorking, please wait... ")
(princ)
)
(progn
(vla-startundomark
(setq acDoc (vla-get-activedocument (vlax-get-acad-object)))
)
(vlax-put aeccUnitsZone 'angularunits 1)
(if (= 1.0 (vlax-get aeccUnitsZone 'drawingscale))
(vlax-put aeccUnitsZone 'drawingscale 20.0)
)
(vlax-put aeccUnitsZone 'drawingunits 1)
(vlax-put aeccUnitsZone 'foottometerconversionflag 2)
(vlax-put aeccUnitsZone 'matchautocadvariables 0)
(vlax-put aeccUnitsZone 'scaleobjectsfromotherdrawings 0)
(vlax-put aeccCoordSys 'cscode coord)
(princ "Done. \n")
)
)
(*error* nil)
)
Cheers