This function returns the number of times an atom has been used.

#define INCL_WINATOM /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HATOMTBL    hatomtblAtomTbl;  /*  Atom-table handle. */
ATOM        atom;             /*  Atom whose use count is to be returned. */
ULONG       ulcount;          /*  Use count of the atom. */

ulcount = WinQueryAtomUsage(hatomtblAtomTbl,
            atom);