Dutch term (edited): fiscaal vertegenwoordigersschap

As it's for a company newsletter, I certainly agree with the style of your approach to the first part of the sentence.

Re the second part, being an import & export business, the company probably also acts as tax agent in the Netherlands for their partners or clients based overseas.

To complete the translation, I would suggest: "Nel deals with important VAT matters and the tax agency side of things". Or: "Nel deals with important tax matters and liaises with the tax authorities for our overseas partners".

Not a word-for-word translation, but it conveys the meaning and is in a style suitable for a newsletter or magazine.

-> "Als buitenlandse ondernemer kunt u voor het voldoen aan uw fiscale verplichtingen een fiscaal vertegenwoordiger aanstellen. Als u een fiscaal vertegenwoordiger inschakelt, hoeft u zich meestal niet als belastingplichtige voor de BTW te laten registreren bij de Nederlandse Belastingdienst. Vaak treden douane-expediteurs, die de import- en exportformaliteiten voor ondernemers verzorgen, ook op als fiscaal vertegenwoordiger."
http://www.belastingdienst.nl/buitenland/5a77fca.htm

-> "If you are required to file a VAT return in the Netherlands or wish to claim a VAT refund in the Netherlands, you do not have to do this yourself. You are free to authorise a third party to represent you vis-à-vis the Dutch tax authorities. An authorised agent can: - apply for a VAT refund on your behalf; - file VAT returns; - complete any other formalities."
http://www.belastingdienst.nl/buitenland_uk/5a6d980.htm