How to perform mathematical operation which is stored as character in R?

I have a table like this,

structure(list(component = structure(1:4, .Label = c("a", "b", 
"c", "d"), class = "factor"), dimension = structure(c(1L, 3L, 
4L, 2L), .Label = c("12*10*05", "30*30*20(2)+32*34*04", "30*30*20+174*153*21+108*014*04", 
"98*98*12(2)"), class = "factor")), class = "data.frame", row.names = c(NA, 
-4L))

I need to perform mathematical operation in column ‘dimension’ which is stored as character and convert to integer. For ex: "98*98*12(2)" should be stored as a result of =(98*98*12)*2 = 230496

The desired output:

structure(list(component = structure(1:4, .Label = c("a", "b", 
"c", "d"), class = "factor"), dimension = c(600L, 583110L, 230496L, 
40352L)), class = "data.frame", row.names = c(NA, -4L))

> within(df, new.dimension <- sapply(gsub("(\d)\(","\1*(",dimension),function(x) eval(parse(text = x)))) 
  component                      dimension new.dimension
1         a                       12*10*05           600
2         b 30*30*20+174*153*21+108*014*04        583110
3         c                    98*98*12(2)        230496
4         d           30*30*20(2)+32*34*04         40352