Hi,
Perhaps I'm just misunderstanding the wording, but idvm_vallink_basic is a view so you cannot update this directly, and you should never update the tables the view is based on directly.
Alternative 1, look up the "Extension framework" for documentation on how to implement java extensions for the IdM NW Web UI.
Alternative 2, add a To IdentityStore pass as part of the task workflow where your logic is implemented in a jscript:
MSKEYVALUE=%MSKEYVALUE%
****AD_USER_ID=$FUNCTION.GENADUSERID(%MX_FIRSTNAME%!!%MX_LASTNAME%)$$
Br,
Chris