Yes, a court can compel witnesses to attend, but they cannot compel them to remember what happened. For this reason witness summonses are rarely used as a reluctant witness is often worse than no witness at all.
For the victim�s statement to be accepted as evidence in court without him attending it has to be �agreed� by both sides. It can then be read to the court as a �Section 9� statement. However, since the principle aim of the defence advocate is to highlight discrepancies, weaknesses and inconsistencies in the prosecution evidence, they have the right to have the witness attend so that they can give �live� evidence and be cross-examined on the contents of their statement. If the defence makes such a request and it is denied, then the statement cannot be admitted as evidence.
It is most unlikely in a case such as you describe that the defence will agree to the statement of the victim being �read�. It is further unlikely that the prosecution will proceed if the victim is unwilling to attend court to give live evidence, or if that evidence is likely to be of little use.