On Wednesday night they secured European football next season after a 2-1 victory over Hearts.
Ricki Lamie hit the winner after a 56th-minute corner to take Motherwell up to fourth in the cinch Premiership and guarantee a top-five spot.
Lamie had scraped Well into the top six with a stoppage-time equaliser against Livingston and the Steelmen again timed their post-split run to perfection with their second and third league wins of 2022 coming in the past five days.
After clinching a place in the Europa Conference League qualifiers, Alexander said: “No-one saw that a month ago, did they? It’s a brilliant feeling. I am so pleased for everybody connected to our club and certainly the players and staff who have put so much into it.
“We have had to put the tin helmets on since January because our results haven’t been great but we kept believing, kept working, kept plugging away and eventually we have got our rewards.
“We spent 24 weeks in the top six before the split, we won enough points over the course of the season.
“The lads have shown great courage to win the last two games and get European football. I know it’s a big thing for us because it’s unexpected given the size of the clubs in this division that can outmuscle us a lot of the time.
“For me, I have won a couple of promotions and this is as good as them without a shadow of a doubt.”