I would like to know a simple way of selecting the odd and even digits from a string of 48 charaters.

Say I have a string for example '1p1p2p3p4p5p4e3e2e1e' of 20 characters. I want to select the odd digit values '1123454321' and
even digit values 'ppppppeeee'.

I tried using substr('str',1,1) || substr('str',3,1) and so on for odd digit values and similarly for even digit values.
I don't know if there is any simple method other than using the substr.

Expecting the expert comments on this.

Thanks in adv.

==> Eeswar