Your first step is assigned a resource out of a pool and you want to pass the resource ensuring subsequent steps run on the same resource as the first step, not just some arbitary resource out of the pool.
You can track the resource in a property attached to the parent step, /myParent, or on the job, /myJob and reference the resource on subseqent steps.
In the first step, record the pool-assigned resource in a property.
ectool setProperty /myParent/whichResource $[/myResource/resourceName]
In the subsequent steps, in the resource, reference the property.