This text is Dragan Nedeljkovich wrote for me, because my English is not the best.
First, I want to thank Dragan, and everyone who are helped in this topic.
Yes, I finally, when I saved a header at the end of the transaction (before commit / Rollback), I call the table counter with Refresh (), increased the counter by one. Then I transfer of the header, the header again saved with tableupdate () and I do commit. If the counter returned null, Rollback to process the document level (header and lines,,,).

I do not use FLOCK () on the counter, do the lock itself TRANSACTION.
Why? Because at one point, the data can be transferred into a RDBMS (MS SQL Srv, postgreskl ...), FLOCK / UNLOCK, them there not used.

Example:
...

oKD=CREATEOBJECT("PromKD")       && Header
...
oKD.oDat.BeginTrans()
...
SELECT CaIdDok                                     && CursorAdapter Counter table IdDok

oKD.oIdDok.NewBrFakCA(this.ckljucimefak )

llOk=IIF(ISNULL(lcId),.F.,.T.)
...

IF llOk
  sele v_promkd                                   && CursorAdapter Header table
  repl next 1 BrFak With lcId
   llOk= tableUpd()
ENDIF

if llOk
   oKD.oDat.Committrans()
ELSE
    oKD.oDat.RollBackTrans()
ENDIF
*****
NewBrFakCA
LPARAMETERS tcKey
LOCAL lnRetVal, ;
   lnwa, ;
   lcid, ;
   lcKey
      
lcKey=tcKey      
lcId=null

lnwa=SELECT(0)      

SELECT Caiddok

LOCAL a,lnnrf
a=0
lnR=-6

DO WHILE a<15 AND lnRl<>0

    SELE CaIdDok

    =REFRESH()
    
     lcId=ALLT(STR(VAL(Vrednost) + 1))

    UPDATE CaIdDok SET Vrednost = lcId

     IF  !TABLEUPDATE()
          =AERROR(aErrA)
       lnRetVal = aErrA[1]
    ELSE
           lnRetVal= 0
    ENDIF

    IF lnRetVal<>0
         SELECT  CaIdDok
         =TABLEREVERT(.t.)
         a=a+1
     ELSE
          SELECT CaIdDok
          EXIT		
    ENDIF

ENDDO
  
SELECT (lnwa)

lcId=IIF(lnRetVal = 0,lcid,null)

RETURN lcId

...

Inside the

DO WHILE a<15 AND lnRl<>0

, an error occurs 130 or 1585.
Question: where and when to call the table counter (CaIdDok)?
Within a transaction, when I call the counter table (CaIdDok), properly done only Refresh(), but CursorRefresh() or Requery() not done.
And... Sorry, my English is not the best.