The striker revealed his disappointment at being left out of Cowan's starting XI at Darlington, where he came from the bench at half-time to bag a remarkable second-half treble.
His winner, which came in the 96th minute in the north east, sparked wild scenes for the travelling players, staff and supporters.
And Dinanga hopes, after being denied back-to-back starts despite scoring in the previous game against Guiseley in the FA Trophy, that he has done enough to force his way in.
"The gaffer pulled me before the game and said I was not starting, which was a bit disappointing as a striker having scored the game before," Dinanga, Telford's 25-goal top scorer two seasons ago, said.
"But he said that's just how the game was going, there was nothing I could do about it then.
"At half-time I was just thinking about coming on and proving myself again.
"It's been hard for me this season but when I scored with my first touch it reminded me of before (two seasons ago), being in the right place at the right time.
"I've never scored a last minute winner. I'll remember it for the rest of my life. It felt like a play-off final. I was out to prove a point and what more can I do now?"
The striker, 22, revealed Cowan's words after the stunning National North turnaround were gratefully received. Dinanga added: "He said I worked hard and that was all that was missing, if I worked that hard last game I would've started.
I wouldn't have scored a hat-trick if I started. It all worked out well.
"It's advice from the gaffer and I'll take it on the chin."