"Send Xu Jue to Dongchuan" is a farewell poem, which is to send Xu Jue to Dongchuan (Dongchuan is not Dongchuan now, but Tongzhou, which is the junction of Suining County in Jiangsu Province and Lingbi County in Anhui Province today). They haven't seen each other for years, but they want to leave at the first sight. Wang Anshi wrote this poem for him! Xu Juezhi's name is Xu Chengquan. But I didn't find any information about this person!
The general translation should be:
"Sanqiu can't see everyone" means I haven't seen each other for many years but I often miss each other (Sanqiu means many years, not three years).
"Shake hands with the mountain and feel melancholy", saying that there is a feeling of parting in the mountain.
"I dare to look forward to it in the future", saying that I hope to meet again when I am old. (Not "Huang Kao", but "Huang Ming", which means old age)
Look at each other and celebrate the Year of the Rooster. The Year of the Rooster refers to the year when Wang Anshi was born in the heart, so this poem should mean that the two have known each other since childhood!
"Steep Stone Stack belongs to Wang Zun", and "Steep Stone Stack" refers to a passage made of wood, which is cut through a stone shelf in the mountain because of the dangerous environment on the way. "Wang Zun in power" is the abbreviation of "Wang Zun in power", which comes from the allusions in Hanshu. For example, this refers to being loyal to officials and not avoiding difficulties and obstacles.
"Rong Lu Golden Gate Zu Ti Whip", "Rong Lu" refers to official career, and "Golden Gate" refers to wealth. "Zu Ti Whip" is also an allusion, which comes from the appreciation in Shi Shuo Xin Yu. The moral here is to encourage Xu Juezhi to make progress.
"A new generation of officials and ceremonies" is the emergence of a generation of officials, with fresh literary talent.
"Chen Yu wants to stay", "Chen Yu" originally refers to the eaves, here refers to the imperial palace, that is, Kyoto, but also refers to prosperity! But people will linger when they see Kyoto.
Therefore, the two words you named are "Chen Yu", which actually means eaves. Not recommended!
The whole poem is an ordinary poem, encouraging friends and praising them for taking pains to complete their mission. It has no special political meaning and ideal ambition, and can't be regarded as Wang Anshi's masterpiece! But this poem embodies Wang Anshi's style of reasoning, rhetoric and allusion!