“公使的”这一表述较为模糊,若从外交职务角度理解,推测你想问的是“公使(minister plenipotentiary,一种外交官衔)相关的” ,以下几种可能的英文表达:
pertaining to the minister plenipotentiary
例句:The documents pertaining to the minister plenipotentiary were carefully organized.(与公使相关的文件都被仔细整理好了。)
belonging to the minister plenipotentiary
例句:The luxurious carriage belonging to the minister plenipotentiary was a symbol of his high status.(属于公使的那辆豪华马车是他高地位的象征。 )
regarding the duties/powers of the minister plenipotentiary
例句:We need to have a clear understanding regarding the duties of the minister plenipotentiary.(我们需要对公使的职责有清晰的认识。)