file_id	IN:	File identifier returned by Hopen
	vgroup_class	IN:	Class name of the vgroup

	Purpose	Returns the reference number of a vgroup specified by its class name.
	Return value	Returns the reference number of the vgroup if successful and 0 otherwise.
	Description	Vfindclass searches the file identified by the parameter file_id for the vgroup with the class name specified by the parameter vgroup_class, and returns the reference number of that vgroup.
		If more than one vgroup has the same class name, Vfindclass will return the reference number of the first one.

	FORTRAN	integer function vfndcls(file_id, vgroup_class)
		integer file_id
		character*(*) vgroup_class