Private keys generated by bitaddress.org’s code work fine as input to zcashd’s importprivkey command, to control an associated t-address.
But, how do you get the matching t-address, short of doing that import and noticing which new t-address appears in the output for getaddressesbyaccount ""?
Well, there is a process for converting a Bitcoin 1-address into corresponding ZCash t-address, as controlled by the same private key.
Inspired by @Voluntary’s C-code for such a conversion, I’ve made a Nodejs version that’s viewable/runnable on the web in a notebook at Runkit.com. See:
Bitcoin 1-Address to ZCash t-Address
Read the caveats there carefully before using the notebook or associated web-service to create t-addresses