Vertimas - Danų-Anglų - Dernæst regner jeg med jævnligt benytte mig af denne funktion.

"Dernæst" could be translated "Furthermore"

The sentence should clearly be understood as a continuation of what the person requesting the translation said first (in the comment field): "dette er min første tekst til oversættelse. Jeg vil derfor i første omgang teste af, hvordan det virker", so in the light of this information, I suggest the following translation: "Thereupon, I expect to make use of this service on a regular basis." The Danish original doesn´t say anything about "soon" and the word "dernæst" has not been translated in the English version (by Bhatarsaigh)

PS: "Dernæst" could also be translated to "thereafter" or "after that" is you don´t like my "thereupon" :-)

For det første; det engelske er ikke korrekt...
For det andet; Det er ikke korrekt dansk sætningen burde være :"....med jævnligt at benytte...".

The word "soon" don´t fit in there. I better like: Then I expect to use this function frequently

Not to bad of a translation.
However I believe a more accurate one would be:
"Soon, I'm expecting to use this function regularly"