how to disable/set-text buttons in MUI_PAGE_INSTFILES?

i have tried now several solutions and none worked.

;disable buttons
## Change Next button text
GetDlgItem $1 $HWNDPARENT 1
SendMessage $1 ${WM_SETTEXT} 0 "STR:----"
## Change Cancel button text
GetDlgItem $1 $HWNDPARENT 2
SendMessage $1 ${WM_SETTEXT} 0 "STR:Beenden"
## Change Back button text
GetDlgItem $1 $HWNDPARENT 3
SendMessage $1 ${WM_SETTEXT} 0 "STR:----"
ShowWindow $1 ${SW_HIDE}

this in a PRE function only works while the dialog is at work.
when all is done (incl my detailprints) all buttons shows like normal - woot

i want the cancel button as "Finish" and back/next disabled.

pls help.

PS even the header text isnt visible - only while in work.

here a shot how it is shown (fast capture) at work.
(the small pic inside ist after processing - not wanted)

Every instfiles page is followed by a "completed" page which has a different set of buttons. You can set those button texts (Next, Back, etc.) to variables and copy the correct text those variables before the "completed" page is reached. The last section should do.

hmm, not sure what you are talking about.
i found some hints about NextBtn InstallBtn aso
the most trouble is to disable back/next and to enable cancel.
this section with detailprint has the option to copy text but it does not need any other interaction - just finish.

[invisible][invisible][Finish]
instead
[greyed][Finish][greyed]

How can I get the LangString containing the `&Next >` string? I see # ^NextBtn in .nlf file but I don't know how to get the string. Thanks.

That's in $(^NextBtn), how simple dear Watson 🙄