In our script libraries, we do not have any code but @Script..., which is a reference to the script that we desire to run. Inside of the scripts that we desire to be executed, the @T macros are said to be invalid syntax. When we had the code programmed directly in the script libraries, it worked fine. Do you know what is causing the problem? If you need examples, let me know.

All macro-parameters are substituted in the job runtime with their value. @SCRIPT is one of them, the contents of the referenced file is inserted into the script. However the substitution is only done on the top level. There is no recursion. That's why external files cannot use macro-parameters.
To take advantage of macro-variables in external files use somethng like the following

//In the calling script define a varible
Dim my_variable, date, "@T"yyyy-mm-dd""
// then reference an external file
@SCRIPT:somefile.jal

In the referenced file just use the variable, for example,
// this is somefile.jal
MessageBox my_variable

: In our script libraries, we do not have any code but @Script..., which is a
: reference to the script that we desire to run. Inside of the scripts that
: we desire to be executed, the @T macros are said to be invalid syntax.
: When we had the code programmed directly in the script libraries, it
: worked fine. Do you know what is causing the problem? If you need
: examples, let me know.

We are only getting an invalid syntax error for T macro-parameters and not V macro-parameters. Do you know why this may be?

How do you use it?
Please provide a code snippet demonstrating the usage.

: We are only getting an invalid syntax error for T macro-parameters and not V
: macro-parameters. Do you know why this may be?

: How do you use it?
: Please provide a code snippet demonstrating the usage.

// This line does not give a syntax error.
logaddmessageDB "ERROR", @V"job_id", "@V"job_name"", Abortit_error_msg

// This line does give a syntax error.
logaddmessageDB "ERROR", @T"yyyy", "@V"job_name"", Abortit_error_msg

I can reproduce this too. I am really surprised that @V macro-variables work in off-line scripts as nested macros are not supported

Anyway, I can offer you the following solution

Dim d, datetime
Dim yyyy, number

Today d
DateTimePart d, "yy", yyyy
logaddmessageDB "ERROR", yyyy, "@V"job_name"", "test"

This will work in both on-line and off-line scripts.

: // This line does not give a syntax error.
: logaddmessageDB "ERROR", @V"job_id",
: "@V"job_name"", Abortit_error_msg

: // This line does give a syntax error.
: logaddmessageDB "ERROR", @T"yyyy",
: "@V"job_name"", Abortit_error_msg

Thank you.