Is there an English translation of "Encargo" by Julio Cortázar? I've not been able to find one online.
An English translation of "Encargo" appeared in New Orleans Review, vol. 6 no. 2, p. 105, with the title "Commission." The translators are Calvin Harlan, Manuel Menan, and Beatriz Varela. The journal is published by the Department of English at Loyola University. Although the issue does not give a specific date, the journal has been published since 1968, so volume 6 is probably from around 1973 or 1974.
The same translation, along with Cortázar's original Spanish version and a French version by Silvia Baron Supervielle, is available on Stéphane Chabrières' blog beauty will save the world.
Stephen Kessler's selection and translation of Cortázar's poems, Save Twilight (expanded edition 2016), also includes both the original Spanish and a different English version of this poem, which Kessler renders as "Assignment" (p. 161).