NEMA 14-30 to IEC C14 power cable?
Don't use a 14-30. This is rated for 30 amps and if protected by a 30A breaker, a 20 amp cord/connector would not be protected properly.

The better choice is a NEMA 6-20 which is 240V 20A rated. You can buy pre-built 6-20 to C14 cables.