[BioC] subsetting lumibatch object by probe ID

[Emanuele Marchi]

Hi Everybody,
I have a list of illumina probe ID's (ILMN_#####) and I'd like to subset 
the matrix of expression values (exprs(lumi.batch.object) by probe ID, 
i.e. row names.
Is there an obvious (and quick) sub-setting method to do that?

If I use plotSampleRelation I can choose a selection of probes (selProbe 
parameter) but I guess it has to be as numeric vector, am I correct?
In fact I tried to put the character vector containing probeID/row names 
and it didn't work...
thank you and really sorry if the question is too basic for you...

Regards,

Emanuele