How strange - I hadn't realised you poor guys were impoverished by the absence of this word! :)


second (SEND)
verb [T] UK
to send an employee to work somewhere else temporarily, either to increase the number of workers or to replace other workers, or to exchange experience or skills:
During the dispute, many police officers were seconded from traffic duty to the prison service.

secondment
noun [C or U] UK
His involvement with the project began when he was on (a) secondment from NASA to the European Space Agency.


(from Cambridge Advanced Learner's Dictionary)