Run DTEXEC from Powershell - convert from batch file

I have the following dtexec command that works fine in a cmd batch file:dtexec /f %DTSPackagesDir%"\%SSISJob%" /Decrypt %DTSPassword% /CONN cm_sql_USTG;%cm_sql_USTG% /Reporting E /Set \Package.Variables[User::strDestinationFolderForFlatFile].Value;%TargetDir%\ /Set \Package.Variables[User::strExtractType].Value;%ExtractType% /Set \Package.Variables[User::strDayKey].Value;%ProcDate%I tried converting it for Powershell and ended up with this:dtexec /f "$cfgDTSPackagesDir\$DTSPackageName /Decrypt $cfgDTSPassword /CONN cm_sql_USTG;$cm_sql_USTG /Reporting E /Set \Package.Variables[User::strDestinationFolderForFlatFile].Value;$TargetDir\ /Set \Package.Variables[User::strExtractType].Value;$ExtractType /Set \Package.Variables[User::strDayKey].Value;$DayKey"The connection string is:Set-Variable -name cm_sql_ustg "Data Source=$cfgDBServer;Initial Catalog=$cfgDBName;Provider=SQLNCLI10.1;Integrated Security=SSPI;Auto Translate=False;Application Name=$AppName"; Write-Output "Connection String cm_sql_ustg: $cm_sql_ustg"I am either getting that the "system cannot find the file specified" and I know it is there, or if I make some changes, it stops on the connection string, not recognizing "Source" (as part of the "Data Source ...." string.Thanks for any help.