Generate archive file name manually in SOA Suite

In one of my project i was supposed to read large files, I implemented it using chunk reading in BPEL.

The issue i was facing in this case was the file was not getting archived, this i achieved using file move operation. However the client was very specific for the naming convention of archive file.

I tried to search for some built in commands but was not successful in generating the same so i used the following expression which generate the same file naming convention as Archive by does by default

concat(xp20:format-dateTime(xp20:current-dateTime(),'[Y0001][M01][D01]'),"_",xp20:format-dateTime(xp20:current-dateTime(),'[H01][m01][s01]'),"_",xp20:format-dateTime(xp20:current-dateTime(),'[f001]'))