McCarthy took his National League South tally to five for the season - nine in total since arriving from National League side Weymouth in the summer - in Hawks' 3-2 league triumph at Chelmsford.
Doswell believes his late runs into the box to finish are reminiscent of England and Chelsea legend Frank Lampard would embark on during his playing days.
The Hawks boss says he's not seen a midfielder with the knack of arriving in the area and finishing ability possessed by McCarthy 'for a long time'.
And Doswell revealed players and staff have now given him the nickname 'Frankie' - as a pointer to what they see as a game likeness to the former Chelsea boss Lampard.
‘He’s the non-league Frank Lampard! Frankie is the nickname he’s been given in the group,’ Doswell revealed.
‘He’s brilliant at these late runs into the box, it’s hard to track his run, what’s good is when he gets there, technically, he’s a very good finisher.
‘I’ve not seen a midfielder for a long time who can arrive and finish as well as he does - I’ve had some good players as well - one of his goals yesterday was not dissimilar to Torquay where he arrived at the penalty spot.
‘I think other managers saw him as a centre-half or a holding midfield player but I started seeing him more as an eight just because of his finishing ability in training. I’d like to think it was a good spot on our part. He’s a good lad as well - all-round he’s just been great so far.’
Hawks' win at Chelmsford was just their second in the past five National League outings - but they had to come from behind in Essex.
Former Norwich and Blackburn striker Simeon Jackson struck on 21 minutes as the hosts went in leading at the break.
But it was then the McCarthy show as he got the first of his 12-minute treble after 59 minutes.
The midfielder then grabbed goals eight and nine of the campaign to hand Hawks a 3-1 advantage.
Jackson struck again in second-half stoppage-time, yet the visitors held on for all three points.
And Doswell felt it was important to record a first league win since October 9.
He said: ‘We’ve won 10 out of 14 now (games) this season but all four of those defeats have come in the league.
‘We know to get in the play-offs you need to get about 65 or 66 points - it’s traditionally always the case.
‘The way that we’re targeting it is to try to get three lots of 18 points in the next markers of our season.’