doing what you describe is a well known BIG FAT ERROR. [grin] don't do that - you already have it all in a nice, solid, easy-to-use $Var ... the $Args collection ... so use it instead of making your code more complex for no reason at all.
What you're looking for is variable indirection, where you refer to a variable indirectly, via its name stored in a different variable or provided by an expression. PowerShell enables this via the Get-Variable and Set-Variable cmdlets, but note that there are usually better alternatives. See the linked duplicate for details.
$VAR0,$VAR1,$VAR2 = $args[0], $args[1], $args[2], this what you mean?$Argscollection ... so use it instead of making your code more complex for no reason at all.Get-VariableandSet-Variablecmdlets, but note that there are usually better alternatives. See the linked duplicate for details.