how to include a ":" as a parameter in powershell?

i have a simple powershell script, like this

sqlcmd -S. -E -Q 'select ''$(x)''' -v x="c:a"

but i always got the error message

Sqlcmd: ':a': Invalid argument. Enter '-?' for help.

i figured out that it is the ":" in the argument caused the problem, but i do not know how to escape it.

thanks, David

Solution

sorry that i have to answer to my own question again.

the only way to solve this problem is to use '+' to concatenate the two string, and the ':' will be reserved.

e.g. $a="abc"+":123"