In order to add new script to the UMX, you must to place corresponding file into /Scripts directory located int UMX installation path.
File must have *.s extension and must contain following structure:

@SCRIPT <scriptname>
@LANG <langid>
<script definition>

You can place two or more script definitions in the same file.

<scriptname> - is the unique script name, it will appear in The Bat with prefix 'FN', for example, if you have defining script 'TEST', you
can place it in your template as 'FNTEST'.

<langid> - is the language identifier, following values are: JS for Jscript, VB for VBscript, PAS for pascal.

<script definition> contains script syntax constructions according language defined in @LANG

For example, to define macros FNTESST returns you 'Hello, World' string, do the following:

Place file TESST.S

@SCRIPT TESST
@LANG JS
hello();
function hello(){
return 'Hello, World';
};

Into /Scripts directory and restart The Bat.

You can optimize this tiny script:

@SCRIPT TESST
@LANG JS
'Hello, World'

It will return you same result.

To use parameters passed to script, you must to use special function GetParams() which initializes two variables: ParamCount and ParamStr. ParamCount will equal to number of parameter passed to script ParamStr[n] - is the array of parameters, first index is 1.
For example, you can list all the parameters passed to script:

@SCRIPT JSPL
@LANG JS
hello();
function hello(){
GetParams();
var i,s;
s='';
for(i=1;i<=ParamCount;i++)s+=i+' - '+ParamStr[i]+'\n';
return s;
};

If you place %FNJSPL('one','two','three') in you template, you will get the following:

1 - one
2 - two
3 - three

It is simply!!!!

At the end, i will show you script allows you to get amount of seconds between tho date-time stamps:

@SCRIPT SECSBETWEEN
@LANG JS
calc();
function calc(){
GetParams();
if(ParamCount<2)return "Wrong number of parameters";
d1=new Date(ParamStr[1]);
d2=new Date(ParamStr[2]);
dt=Math.abs((d1.getTime()-d2.getTime())/1000);
return Math.round(dt);
};

Now, you can write %FNSECSBETWEEN("18/02/1981 14:00:15","25/01/1985 16:00:00")
And you will know that there is 144644385 seconds between these two dates.