Exemplary embodiments of the present invention are directed to an adjustable retaining bracket that can be secured to a surface and adjusted in a first elevational direction relative to the surface, in a second direction along an axis substantially perpendicular to the first elevational direction and towards or away from the surface and in a third direction substantially perpendicular to the second direction. The adjustable retaining bracket may include a base brace and at least one adjusting bolt configured to secure the adjustable retaining bracket to the surface. The adjustable retaining bracket may also include an outer tube operationally engaged with the base brace and an adjusting rod configured to move the outer tube along the third direction, and an inner tube in telescoping relationship with the outer tube and configured for movement relative to the outer tube along the second direction.