You need to contact Clerical Medical and ask them what their requirements are to transfer your fund over to your Eagle Star PRSA.
If you transfer the money into your PRSA it will be allocated a new policy number and will presumably attract a 1% annual management charge.
Depending on the type of plan you had in the UK and the amount transferring, you may be able to transfer it into a Personal Pension or a Buy Out Bond with Eagle Star instead with lower ongoing charges. Exactly the same Eagle Star funds, just lower charges. Talk to the person who sold you the PRSA about this.