Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
a-stĭtŭo (better than adst-), ŭi, ūtum, 3, v. a. [statuo], to place a person or thing somewhere (very rare, perh. only in the foll. exs.): Juben an non jubes astitui aulas? Plaut. Capt. 4, 2, 66 Fleck.: reum ad lectum ejus (aegroti) astituemus, Auct. ad Her. 3, 20 B. and K.; App. M. 9, p. 222, 1; 3, p. 130.