Create a Permanent Powershell Alias from the Command-Line

First, open your Powershell profile in your editor:

code $PROFILE
# Or use micro / vim / notepad / etc.

Next, add the following function and alias:

function _alias {
	Add-Content -Path $PROFILE -Value ""
	Add-Content -Path $PROFILE -Value "function _$($args[0]) {$($args[1])}"
	Add-Content -Path $PROFILE -Value "Set-Alias -Name $($args[0]) -Value _$($args[0])"
}
Set-Alias -Name alias -Value _alias

Run . $PROFILE (remember the dot) to reload your profile.

Now simply add new aliases with:

alias alias-name 'command(s)-to-run "$args"' && . $PROFILE # to load the new alias
# $args is optional but will pass anything after the alias through to the command.
# Note the use of single quotes.

Examples:

alias testing 'echo "1, 2, $args!"' && . $PROFILE
# > testing 5
# Output: 1, 2, 5!

alias gc-m 'git commit -m "$args"' && . $PROFILE
# > gc-m "init"
# Equal to: git commit -m "init"

More info: Using Powershell Aliases in a Pipeline