I don't understand why you can't accessing table, but here it is an idea:
old_alias = ALIAS()
old_error = ON("ERROR")
flag_error = .f.
ON ERROR flag_error = .t.
USE MyTable EXCLUSIVE IN 0
IF NOT USED("MyTable") .OR. flag_error
**** Table is not accessible
ELSE
**** Table is accessible
ENDIF
ON ERROR &old_error
IF NOT EMPTY(old_alias)
SELECT (old_alias)
ENDIF
HTH
Boris
Against Stupidity the Gods themselves Contend in Vain - Johann Christoph Friedrich von Schiller
The only thing normal about database guys is their tables.