Selim,

Maybe a wrapper class can help? Something like this (not tested carefully, no error handling, nothing, just an idea)

The wrapper will keep a count of accesses and assigns of the property nValue of the class 'myClass' which is the one you are not supposed to have access to, I just defined here for testing purposes only.

The idea is that the wrapper has a member that is set to an instance of the mysterious class in it's init, and it also has a property with the same name as the one you want to control, and you add an access an assign method to it, where you can do whatever you want but also set the property of the master class. Now, to use the wrapper as a 'Delegate' you add a this_access method that will check if the property is "native" (ie belongs to the wrapper class) in which case it will return this, other wise it will assume it is a property or method of the "master" class so it will return that object (this.myClassInstance in the sample)

clear
loMyWrapper		= Createobject('myWrapper')

? loMyWrapper.nValue
loMyWrapper.nValue = 9
? loMyWrapper.nValue
? loMyWrapper.ShowMessage('Testing') && ShowMessage is a method of myClass
? 'nValue access count: ', loMyWrapper.nValueAccessCount
? 'nValue assign count: ', loMyWrapper.nValueAssignCount

define class myClass as Session
	nValue = 0
	
	function showMessage(tcMessage)
		Messagebox(tcMessage)
	endfunc
enddefine

define class myWrapper as Session
	protected myClassInstance, Ready
	myClassInstance = null
	Ready = .f.
	nValueAccessCount = 0
	nValueAssignCount = 0
	nValue = 0

	function init()
		this.myClassInstance = Createobject('myClass')
		this.nValue = this.myClassInstance.nValue
		this.Ready = .t.
		return .t.
	endfunc
	
	function nValue_Assign(txNewValue)
		this.nValueAssignCount = this.nValueAssignCount + 1 
		this.nValue = txNewValue
		this.myClassInstance.nValue = txNewValue
	endfunc

	function nValue_Access()
		this.nValueAccessCount = this.nValueAccessCount + 1 
		return this.myClassInstance.nValue
	endfunc

	function this_Access(tcProperty)
		return Iif(this.Ready and not Pemstatus(this, tcProperty, 5), this.myClassInstance, this)
	endfunc

enddefine