If This is the PageFrame object, than here you have two versions of what you're looking for:

with This
	for each loPage in .Pages
		if loPage.Caption = blabla
			Do some code here
		endif
	endfor
endwith

or, using a "standard" FOR:

with This
	for lnI = 1 to .PageCount
		lcPage = "Page" + ltrim( str( lnI, 2))
		if .&lcPage..Caption = blabla
			Do some code here
		endif
	endfor
endwith

Vlad