phone-numpad-words.ps1

$keys = @{
  '1'=''      ; '2'='[abc]'; '3'='[def]' ;
  '4'='[ghi]' ; '5'='[jkl]'; '6'='[mno]' ;
  '7'='[pqrs]'; '8'='[tuv]'; '9'='[wxyz]';
}

$nums = '76937'


$pattern = foreach ($char in $nums.GetEnumerator())
{
    $keys["$char"]
}

$pattern = "^$($pattern -join '')$"
$pattern

$words = [IO.File]::ReadAllLines('C:\path\to\wordlist.txt')
$words -match $pattern