Is this in author instructions somewhere? – I would see this as confusing, and would probably prefer to indicate this as [2, p. 23] Which would be represented by [Bibliography Number|,*p^pp*Cited Pages|] I think. The * represents the “link adjacent” which appears in the citation template as a centered tiny diamond shape and has to be inserted manually from the insert field drop down. The | is the “separation” pipe character and can be typed from the keyboard or inserted from the insert field drop down.