The visitors made 167 for six before Scotland, set a Duckworth/Lewis victory target of 173 to win finished on 133 for nine to give Moores's men a win by 39 runs yesterday.
Scotland lost both openers to James Anderson (two for 22) as they slumped to 18 for two against an England side they will next face again in the pool phase of the 2015 World Cup.
And after a revival led by man-of-the-match Michael Leask's blistering 42 off 16 balls, including five sixes and two fours, they were ultimately undone by off-spinner James Tredwell's one-day best figures of four for 41.
Eoin Morgan made a brisk 31 while Somerset seamer Josh Davey took three wickets for 21 runs after England lost the toss.
More From This Section
"It would have been wrong if the game hadn't taken place," said Cook.
"It was as wet as I've ever fielded in and it probably wasn't fit to play but both sides just got on with it," the left-handed opener added.
Earlier, Bell straight drove Majid Haq for six and next ball reverse swept the spinner for four.
Bell faced 34 balls including four fours and two sixes.
Cook's 47-ball innings ended when a flat, hard drive off left-arm seamer Taylor that was heading for six was brilliantly caught by a diving MacLeod at long off.