UD field in external bpm in linq

Hello,
I am trying to use a UD field in linq statement (in an external bpm).
Note that I am not searching in the database, but in a dataset.

scenario 1:
ttQuoteDtlDsRow = (from row in oQuoteTs.QuoteDtl
where row[“myUDfield_c”].ToString() == “myvalue”
select row).FirstOrDefault();

scenario 2:
ttQuoteDtlDsRow = (from row in oQuoteTs.QuoteDtl
where row.myUDfield_c == “myvalue”
select row).FirstOrDefault();

Both scenarios do not work (scenario 2 does not compile). Does anyone know an alternative way of how to use a UD field in a linq statement. Or how to use it at all in a select.

Regards,
John

https://www.epiusers.help/t/copy-ud-field-value-from-one-table-to-ud-field-on-another/55163/2

Thanks Daryl,
You have shown me a usable solution !

Regards,
John