This is where I got so far:

$DBScriptFile = "C:\Scripts\test.sql"

$replacement = invoke-sqlcmd -query "Select CountryCode From [DBUtilities].[dbo].[EnvBuild] Where Id = (select MAX(Id) from [DBUtilities].[dbo].[EnvBuild])"

$Query = $DBScriptFile -replace "{CountryCode}",[string]$replacement[0]

Invoke -Sqlcmd -ServerInstance localhost -database master -InputFile $Query

The last command does not work, because $Query holds the path to the file:

C:\Scripts\test.sql

I need it to hold the actual text of the script instead. C:\Scripts\test.sql still has {CountryCode} in it. I could output the result of the replacement back into the file, but I don't want to save the file. I don't want to make numerous copies of the file either. I just want to be able to put the script into a variable and run it.

Any ideas?