Perl Substitution

Hi,
Iam a research scientist trainee working on reaction kinectics, I just
started to learn perl, I had asked a few doubts previously and got them
cleared , thanks to all the people who helped, i require your help
again.
I have an input file which has the following form :
....
....
Species1.Concentration moles;
Species2.Concentration moles;
.....
Species3.variable;
Species2.Concentration=Species1.Concentration^Species3.varaible;
....
Species3.variable=4;

(^- raised to the power of)
I need to substitute the variable value in place of the variable and
change the units of Species2.Concentration to moles^4.
I do not know the name of the Species so i don't know how to use
regular expression and also the variable might be more than 1.
Please help me out. Thanks in advance.

.