First, you need to export the OSRS sequence data, base data, and frames data of that particular animation, perhaps take a look at this here
Bases > Goes into idx0 in 718
Frames > Goes into idx1 in 718
Sequences > Goes into idx20 in 718
Bases are packed into archive: baseid, file: 0
Frames are packed into archive: framecollection (frameid >> 16), file: framekey (frameid & 0xffff)
Sequences are packed into archive: seqid >>> 7, file: seqid & (1 << 7) - 1
You could use Alex cache library which can be found in the Matrix release to pack the data into the 718 cache.
If you have any questions, drop me a message on Skype or in a PM in here.