Unusual word - help needed

[venetia ansell]

Can anyone help me with the form of ātasthuṣīṇām from Vedanta Deshika's
Hamsasandesham 1.20?  The verse and translation are below and I've added the
glosses that two commentaries give:

ikṣu-cchāye kisalaya-mayaṃ talpam ātasthuṣīṇāṃ

saṃlāpais tair mudita-manasāṃ śāli-saṃrakṣikāṇām |

karṇāṭ’-āndhra-vyatikara-vaśāt karbure gīti-bhede
muhyantīnāṃ madana-kaluṣaṃ maugdhyam āsvādayethāḥ

*Relish the simplicity, stirred up by love, of the girls who guard the rice.
They revel at heart in all sorts of gossip as they sit in the shade of the
sugarcane using sprouting shoots as seats, forgetting themselves entirely in
the strangely blended songs formed from a mix of the **Karṇāṭak** and **
Āndhra** tongues.*

One commentary glosses 'āśritānāṃ' and another 'āsthitavatīnām'.

Thank you very much,

Venetia Ansell