Most Valuable Professional

View Jan Karel Pieterse's profile on LinkedIn subscribe to rss feed
Subscribe in a reader

Subscribe to our mailing list

* indicates required

File crashes Excel!!

Save my workbook!
The best tool for salvaging problematic workbooks.


Excel VBA Masterclass (English)
Excel VBA for Financials (Dutch)

Third party tools

Speed up your file

The best tool to optimise your Excel model!

Repair your file

Stellar Phoenix Excel Repair
Best tool to repair corrupt Excel sheets and objects

Your Excel Expert; uw Excel specialist

Welcome to the website of

JKP Application Development Services.

If you are looking for an Excel specialist and an Excel and VBA expert you've come to the right place.

My core business is developing solutions using Microsoft Excel/VBA and Access/VBA. Integration with other (Office) programs is possible.

Need expert Excel help? Get in touch .

My Services page lists some example projects.

Need Excel or VBA training? Information about our Excel and VBA trainings can be found on our trainings page.

If you need more information about me, look at my English homepage .

To find out whether you've actually found an Excel expert, I invite you to browse through my Excel articles .

I also recommend to try my free utilities .

Click here for remote assistance Click for remote assistance

Welkom op de website van

JKP Application Development Services.

Als u op zoek bent naar een echte Excel specialist en een Excel en VBA expert dan bent u aan het juiste adres.

De nadruk ligt op het ontwikkelen van toepassingen in Microsoft Excel/VBA en Microsoft Access/VBA. Ook integratie met andere (Office) programma's is mogelijk.

Kunt u de hulp van een Excel expert gebruiken? Neem dan contact op .

Op de Diensten pagina vind u voorbeelden van projecten.

Zoekt u Excel of VBA cursussen? Informatie over onze Excel en VBA trainingen kunt u op onze training pagina vinden.

Wilt u meer over mij weten ga dan naar mijn Nederlandse homepage.

Wilt u zelf beoordelen of u een echte Excel expert heeft gevonden, bekijk dan mijn Excel artikelen .

Probeer ook eens mijn gratis hulpprogramma's .

Klik hier voor hulp op afstand Klik voor hulp of afstand

What's new on this site:

(English and/or Dutch content)

Nieuw op deze site

(Engelse en/of Nederlandse artikelen)

Updated article: Working with Circular references in Excel
I have updated the page on VBA driven circular reference calculations
Tue, 22 Oct 2019 11:45:00 GMT

Update: RefTreeAnalyser
RefTreeAnalyser 2.0 has just been updated. Fixed issue where references are not found when formula contains new line character (alt+enter).
Thu, 26 Sep 2019 12:15:00 GMT

And the winner is...
Today I've posted the solutions I received for my Excel challenge of August 2019 named Combinations, Combinations.
Thu, 19 Sep 2019 14:00:00 GMT

Updated: Compare Two Tables
I've enabled the Compare2Tables tool to work on 64 bit Excel.
Tue, 03 Sep 2019 14:50:00 GMT

Updated: Pivottable Slicers, Synchronizing slicers
I have added a download file to the article on how to synchronize slicers from different caches.
Thu, 29 Aug 2019 15:05:00 GMT

Update: RefTreeAnalyser
RefTreeAnalyser 2.0 has just been updated. I have improved the Check Formulas interface.
Tue, 06 Aug 2019 16:19:00 GMT

Update: RefTreeAnalyser
RefTreeAnalyser 2.0 has just been updated. I have fixed a small bug pertaining to hard-coded strings in formulas.
Mon, 29 Jul 2019 16:45:00 GMT

Update: CorruptFiles
I have updated my little article on corrupt Excel files.
Mon, 29 Jul 2019 16:45:00 GMT