How do I assign a variable to a tasks input field?

Problem:

I am trying to load the output variable of a previous task (a provisioned IP addess) into the powershell task to do further customization.  The input field won't accept the standard variable notation (I've tried many permutations).  I might be misunderstanding this completely, so please point me in the right direction.

Solution:

Well, after a long day of learning - and seeing how far off I was - here's core dump of what I was missing.  I will try to clean this up later, but hopefully it will help any other lost souls.

**** HOW TO BUILD A WORKFLOW PROPERLY ****

Note- A standard catalog item will always be attempting to provision a VM.

It will pass a VM Context to any post-provision task that is configured.

When creating a workflow for a post-provision task, be sure to select the Select VM Context option on the front workflow page.

From there, you can use the variables from the context as admin input values.  Those are:

    ${VM_HOSTNAME}

  ${VM_HOSTNAME_SHORT}

  ${VM_HOSTNAME_DOMAIN}

  ${VM_IPADDRESS}                         

  ${VM_ID}

  ${VM_NAME}                                           

  ${VM_STATE}

  ${VM_STATE_DETAILS}

  ${VM_PARENT}

  ${VM_CLOUD}

  ${VM_GROUP_NAME}

  ${VM_GROUP_ID}

  ${VM_VDC_NAME}

  ${VM_VDC_ID}

  ${VM_SR_ID}

  ${VM_SCHED_TERM}

  ${VM_TYPE}

  ${VM_COMMENTS}

  ${VM_CATALOG_ID}

  ${INITIATING_USER}

  ${SUBMITTER_EMAIL}

  ${SUBMITTER_FIRSTNAME}

  ${SUBMITTER_LASTNAME}

  ${SUBMITTER_GROUPNAME}

  ${SR_ID}

  ${GROUP_NAME}

  ${USER}

  ${APPCODE}

  ${COST_CENTER}

  ${UNIQUE_ID}

  ${LOCATION}

  ${PROFILE_NAME}

  ${COMMENTS}

  ${CATALOG_NAME}

  ${CLOUD_NAME}