I have a requirement to rename a file based on previous file name.
Is it possible?

For example
xx2014-10-07TEST.txt
will be renamed
xx07-10-2014tst.txt

I cannot use the current date function because I may have to process older files.

kgough,

You're option here is to parse the original file name. Something like:

Set FYear = Substring( FName, 3, 4 )
Set FDay = Substring( FName, 8, 2 )
Set FMonth = Substring( FName, 11, 2 )

Then, create your new file name:

Set NewFile = ${ Concat( 'xx', FMonth, '-', FDay, '-', FYear, 'tst.txt' ) }

That is exactly what I want.
Should I run the "Set" commands by adding them as "Execute Native Command" steps?

Not at all .. just use the SetVariable Task

<setVariable label="set FDay" name="FDay" value="${Substring( FName, 8, 2 )}" version="2.0" />

When I try that I get an error:

<setVariable label="Set JJ-Day" name="JJ" value="${Substring( LocalFile, 24, 2 )}" version="2.0" />

Variable not found: Substring( LocalFile, 24, 2 )

My main project is Version 1, is that the problem?
Then if I switch to V2 I get an error in my ExecuteOnlyIf
executeOnlyIf="${myLocalFileCount} ge 1"

Ken,

Upgrading to version 2 will get you a bit more functionality with your Expression Wizard.

When editing the Version 1 project, click on the Upgrade button and convert to Version 2. Then, your Expression Wizard will give you the options you need for the Functions (Substring, Contains, etc)

Don't forget that the syntax of the command changes with this.

${var} eq 'x'

now becomes...

${ var eq 'x' }

Let us know if you have any other questions.

That worked.
Thank you very much!