We report on the appearance and stabilisation of twist-grain-boundary-A (TGB ) phase in confined geometry samples of the liquid-crystalline compound CE8, by means of polarised optical microscopy. The chiral liquid crystal (LC) compound was chosen such as to undergo a cholesteric-smectic-A transition with temperature (type-I smectic), and to be close to the triple point between the cholesteric, TGB , and smectic-A phases. We used several types of anchoring conditions and various effective anchoring strengths. The results reveal that (i) the TGB phase exists as a metastable phase with strong fluctuations in the bulk, and (ii) it can be stabilised by the sample boundaries for adequate anchoring conditions. This means that we probably observed a type-I to type-II smectic transition induced by the substrate. Some dependence of the stabilisation on the surface-anchoring conditions and on the cell thickness is reported.