Problem:

You need to get a UNC path from a mapped network share's drive letter.

Resolution:

Use the Microsoft API WNetGetConnection. This function retrieves the remote name of the network resource associated with a local name. You can obtain this API from here:

http://msdn.microsoft.com/en-us/library/aa922031.aspx

Example (code is also provided as an attachment to this article)

         COPY "windows.cpy".
       identification division.
       SPECIAL-NAMES.
           call-convention 74 is STDCALL
           call-convention 66 is cc66.



       
       working-storage section.
       78 SZ value 25.
       01 lpLocalName  pic x(5).
       01 lpRemoteName pic x(SZ).
       01 lpnLength    DWORD value sz.
       
       01 proc-pointer procedure-pointer value NULL.
       78 MPRdll       value "MPR.dll".
       01 retDWORD     DWORD. *> DWORD = pic  9(9)  comp-5
       


       procedure division.
          set proc-pointer to entry MPRdll
          if  proc-pointer = NULL
               display "ABNORMAL end: failed to load " MPRdll
               stop run
          end-if
          
          move z"S:"  to lpLocalName
          call cc66 WNetGetConnection using lpLocalName
                                            lpRemoteName
                                            lpnLength
                                      returning retDWORD
          evaluate retDWORD
          when NO-ERROR display "OK "  lpLocalName
                                       " <-> "
                                       lpRemoteName(1:lpnLength)
       …