Attacking midfielder Williams netted four times in as many games during his one-month loan spell with Evesham United, where Collicutt is now manager.
"I have a lot of time for the lad and I've already told Mark (Yates) I'd love to have him back for another loan spell," Collicutt said.
"He definitely has something there and he has the best knack of all in football, that of scoring goals.
"He is an intelligent footballer, who reads the game and Mark Boyland has been raving about him, so I hope he gets his chance in the first team."
Williams, 18, grew up in Charlton Kings and attended Balcarras School.
After a prolific season for the youth team last term, he was handed a one-year professional contract and has so far made five first team appearances.
"Harry's loan spell was a bit stop-start because he didn't play in our FA Cup games, but based on the games he did play in the league, he's definitely one to look out for in the future," Collicutt added.