Finally i found out that i need to dig into DynamicControl to get underlaying controls. So i solved my problem using following code:
foreach (Control ct in cont.Controls)//cont is the DynamicControl
{
foreach (Control ci in ct.Controls)
{
if (ci is CheckBox)
((CheckBox)ci).Enabled = enable;
if (ci is TextBox)
((TextBox)ci).Enabled = enable;
}
}
This way i have disabled controls but it suits me as well.